Implementing a workload control system
Company X
December 2008
Primary Supervisor:
Prof.Dr.Ir. J. Slomp
Secondary Supervisor: Dr. J.A.C. Bokhorst
Company Supervisor: H. Busschers
Company X
Company X
Preface
In front is the result of my graduation project which I’ve done to finish my study Technology
Management. During the last period of my study I worked at Company X Y, where I learned a lot about change. In the period from May until September I supported the implementation of a new workload control system called Takt. I would like to thank the company, Jannes Slomp and Jos Bokhorst for their support during the last part of my study.
Groningen, December 2008
Company X
Company X
Management Summary
Company X
Table of contents
PART I Introduction & initial state ... 6
1 Introduction ... 7
1.1 Company X ... Fout! Bladwijzer niet gedefinieerd. 1.2 Y & CXS ... 8 1.3 Problem introduction ... 8 1.4 Management goal ... 10 2 Research outline ... 12 2.1 Objective ... 13 2.2 Action Research ... 15 2.3 Recent studies ... 16
2.4 Recent results of TAKT at MACHINE COLLECTION-3 ... 17
2.5 Thesis outline ... 18
3 Production characteristics of MACHINE COLLECTION-2 ... 19
3.1 Work order release initial state ... 21
3.2 Product, Process and Performance initial state ... 22
3.3 Comparing MACHINE COLLECTION-2 and MACHINE COLLECTION-3 ... 23
3.4 Organization initial state ... 26
3.5 Conclusion initial state ... 26
PART II Process of change ... 28
4 Change process ... 29
4.1 Theory about change ... 29
5 Creating Awareness ... 33
6 Introduction cards ... 37
6.1 Summary Introduction cards ... 52
6.2 Analysis Introduction cards ... 55
7 Screen introduction ... 58
7.1 Problems screen ... 60
7.2 Analysis introducing screen ... 63
8 Analysis of the change process ... 65
8.1 Desire to change and the creation of commitment ... 68
PART III Results & Conclusion ... 70
9 Results ... 71
10 Evaluation, and recommendations ... 75
10.1 Evaluation... 75
10.2 Recommendations Takt-system ... 75
10.3 Recommendations implementation WLC ... 76
11 References ... 78
12 Appendices ... 79
12.1 Appendix 1 “Task number and corresponding machine” ... 80
12.2 Appendix 2 “Interrelation between streams” ... 81
12.3 Appendix 3 “Starting operation” ... 82
Company X
PART I
Company X
1 Introduction
This thesis describes the implementation of a workload control system in a manufacturing department of Company X Y.Workload control concepts buffer the shop floor against external dynamics by creating a pool of unreleased jobs. The use of workload norms should turn the queuing of orders on the shop floor into a stationary process which can be characterized by an equilibrium.1 The
introduction of the workload control system is aimed at realizing shorter and more reliable lead times. This thesis is split up into 3 parts. The first part consists of 3 chapters. Chapter 1 will introduce the company and its strategic objectives. After the strategy has been given, the problems management is dealing with are mentioned. MACHINE COLLECTION-2, the department at which the workload control system is implemented can be characterized as “low volume, high variety”. MACHINE COLLECTION-2 is part of the manufacturing department CXS and is introduced in this chapter after a short
introduction of successively Company X, Y & CXS. Chapter 2 describes the research outline and recent studies. Part 1 will end with chapter 3 which describes the production characteristics of MACHINE COLLECTION-2 and its initial state. Part 2 will describe and reflect the change process. The stages will be noticed later. The last part of this thesis contains the results & conclusions of implementation of the workload control system at MACHINE COLLECTION-3. Figure 12 called “Thesis outline” (p. 18) reflects visually the classification of the report.
1.1 Company
X
………..
Company X
……….3
1.2
Y & CXS
The brand name Y is under the name Company X …….. part of the Company X Corporation. Company X Electric engineers, produces and sells for more than 100 years products to ……., …….. and ………. Under the brand name Y is Company X in Z a partner for ………. and ………..4 Company X Supply (CXS) produces and delivers products to product lines such as Average (A) and Below Average(BA). The Vision of CXS is “to be the fastest and most reliable supplier of parts for Company X Y”. CXS has 4 product lines:
• MACHINE COLLECTION*-1 Type1 • MACHINE COLLECTION*-2 Type 2 • MACHINE COLLECTION*-3 Type3 • MACHINE COLLECTION*-4 Type 4
In 2007 CXS introduced (with support of the University of Groningen) a workload control system at MACHINE COLLECTION-3 Type3. This system is called the “TAKT” system. The system regulates the number of orders at the shop floor. The management of CXS is very enthusiastic about the results (which are mentioned further on in this thesis (2.4)) and wants to introduce the Takt-system also at MACHINE COLLECTION-2 Type 2. The products of Type 2 are mostly small …. components which are delivered to the assembly line or ….. Typical operations in MACHINE COLLECTION-2 are sawing, drilling, tapping, conventional turning, CNC turning and CNC milling. There are a lot of different routings which are mentioned in more detail in chapter 3.
1.3 Problem
introduction
Management of Company X has the strategy to “position Company X as a premier diversified industrial enterprise. A company committed to attaining 10 percent sales and 15 percent earnings growth, while growing returns on investment increasingly beyond the cost of capital”5. Some of the strategic objectives are mentioned in the table below:
Table 1 Strategic objectives Company X Y Z
Strategic objectives: 2007 2008 2009 2010
Company X
CXS wants to increase the OTP. On Time Request (OTR) can be defined as the % of orders that are delivered at a by the customer specified (desired) date. On Time Performance (OTP) can be defined as the % of orders that are delivered on a pre-arranged time (which can be later then the desired delivery date).
For example, if a customer wants a product to be delivered on the 2nd of September the supplier could say that this is not possible. The supplier could decide together with the customer to deliver on
another day, for example the 4th of September. If the customer get the product on the 4th of September the desired date (2nd of September) is not realized but the pre-arranged date (4th of September) is realized.
Customer desired date =OTR criterion (e.g. t=2) Pre-arranged time =OTP criterion (e.g. t=4)
Delivery (e.g. t=4)
Effect OTR criterion not realized Effect OTP criterion realized
Management of the Company X plant in Z wants to improve the OTP (thus do what is predetermined with the customer). The importance of this performance indicator is underlined by the home page of the intranet; the table showed on this website is the OTP table. Table 2 shows this table. Unfortunately it only shows the performance of the assembly lines and not the performance of CXS.
Table 2 OTP Location wide in 2008
OTP
May June July Aug
Company X
Figure 3 OTP of CXS
As can be seen the current level of OTP is far below the goal. To help realizing a better OTP on plant level, management decided that CXS has to implement a workload control system. The effect of introduction should be an increase in OTR and decrease in the level of lead time at MACHINE COLLECTION-2. Lead time is the nominal time between when an order for an item is released (sent out or initiated) and when it is received (completed).6 Throughput time can be defined as the required period for a material, part, or subassembly to pass through the manufacturing process.7 The actual level of OTP and lead times as well as the goal of these variables is mentioned in chapter 1.4.
1.4 Management
goal
The OTR performance of MACHINE COLLECTION-2 has to increase from 60 to 80%. The
management also wants to drop the total lead time (yellow bars in Figure 4 below) from 10 to 5 days. The success of the Takt-system at MACHINE COLLECTION-3 drives the expectation at the
Company X
Figure 4 OTR Figure 5 Lead time
Company X
2 Research
outline
This chapter describes the research objective. It will highlight the main components that should fit to the new workload control system. After describing the kind of research, this chapter will mention recent studies (in 2.3) and the results of the workload control in MACHINE COLLECTION-3 “Type3” (in 2.4). This chapter will end with a visual representation of the outline of this research.
As mentioned in 1.3 the strategy of the Company X plant in Z is to improve the OTP. CXS supports this strategy by trying to become the fastest and most reliable supplier of components for Company X Y. The Takt-system is a workload control system. If orders arrive at MACHINE COLLECTION-2 they are planned and pushed forward to the shop floor. At the shop floor the orders are produced after which the product is delivered to the internal customers. The OTR & lead time performance of MACHINE COLLECTION-2 to the customer was in June 2008 respectively around 60% and 10 days (noticed in 1.4). This performance should increase by the implementation of a Takt-system. Increasing the performance of CXS should help the Company X plant in Z to improve their OTP.
Workload control should turn the queuing of orders on the shop floor into a stationary process which can be characterized by an equilibrium.9 The workload control should make a tight fit between product and process to realize this equilibrium. The type of WLC is therefore depending on product and process characteristics as could be seen in Figure 6.
Figure 6 influence of process and product characteristics on the WLC system
The WLC can be introduced step by step. To realize the desirable results people should be willing to support successive stages. These stages are (1) introduction of cards, (2) lowering Work in Process (WIP) and (3) introduction of the screen. Each of these stages will be noticed in part 2. These stages can be split up into smaller parts which contains the needed actions to realize a phase. Each action will help getting closer to an operational Takt screen. Actions might cause reactions in the organization which in turn would trigger a new action. This action-reaction loop is made over and over again till the WLC system is fully introduced. There are several groups of stakeholders such as operators,
Company X
visualized in the conceptual model. The dotted line represents the consequences of a (partial) implementation of the WLC system on people.
Figure 7 Conceptual model
The implementation of the Workload control is separated in several consecutive stages. These stages will be noticed in part 2.
2.1 Objective
CXS is partner of the X. The X supports the implementation of the new workload control system (called Takt) at MACHINE COLLECTION-2. The present research has 2 objectives which complement each other. The fist one is to help CXS with the introduction of the new Workload control system and the second one is to contribute to scientific knowledge.
The purpose of my research is to:
Support CXS at shortening lead time and improve the OTR performance.
The Research question of this research is:
What is the influence of the organization on the workload control implementation?
Sub questions:
The first sub question therefore has to give insight in the initial situation at MACHINE COLLECTION-2. Therefore, the first sub question is:
Company X
Chapter 3 will handle this sub question and describes the Production characteristics of MACHINE COLLECTION-2.
The Takt-system is already introduced in MACHINE COLLECTION-3. Simply copying the system is expected to be the easiest way to implement the Takt-system in MACHINE COLLECTION-2.
However, MACHINE COLLECTION-2 is not the same as MACHINE COLLECTION-3 (chapter 3.3 will give attention to some important differences). The Takt system of MACHINE COLLECTION-3 has to be adjusted to fit to the MACHINE COLLECTION-2 situation. Chapter 3.4 will notice the most important stakeholders who could influence the implementation of the Takt-system. After the type WLC has been chosen it could be implemented. The conceptual model suggests that people are influencing the successive steps during the implementation of the WLC system. After each step a following step will be taken and this might trigger a new reaction of people. Because of this, people could have a big effect on the implementation of the WLC system. Probably the implementation of the WLC system will influence the behavior of people. To verify these expectations the following sub question is defined:
2. How to organize change?
This question will be answered in part 2 of this thesis. The change process is split up in several successive stages. These stages are: a pre-phase to create awareness, the usage of cards phase and the constant WIP & Screen introduction phase. The awareness stage will be mentioned in chapter 5. Chapter 6 will notice the introduction of cards. Chapter 7 will describe the introduction of the screen. Action Research (AR) is used to be able to monitor the successive stages, and to give answer to this sub question. AR is explained in detail in paragraph 2.2. The implementation of the workload control system is a change process. Recent literature will be used to define several categories which influence the performance of a change process. These categories contain success factors which will be used to monitor the change process at MACHINE COLLECTION-2 The ADKAR model which will be noticed in more detail in 4.1 suggests that change should start with creating awareness. The creation of awareness is noticed in chapter 5. The several studies and the results realized in
MACHINE COLLECTION-3 could be seen as a phase that caused the introduction of the Takt-system at MACHINE COLLECTION-2. These studies and results of Takt in MACHINE COLLECTION-3 are therefore noticed in 2.3 and 2.4.
The outcome of the change process can be compared to the initial situation which is described in chapter 3. To give insight in the final results the last sub question will be:
3. What are the results of the implementation of the workload control system at MACHINE COLLECTION-2?
The answers on this final sub question will be given in chapter 9.
Company X
total lead time between the customer request and receiving an order is depending on more aspects. For example, the time an order is in the planned buffer and the time it takes to release an order (print it, attach drawings and collect material(s)). In Figure 8 below a representation of these order handlings is presented (number of days is indicative).
Removed
Figure 8 total lead time orders
As can be seen in Figure 8 the time an order is on the shop floor is not the only aspect that influences the performance to the customer. Takt does influence this performance but the management should be aware of the fact that for the customer also other aspects, such as waiting time in the “planned buffer” and the time between release & start production, are important performance criteria for the customer. Takt can not influence these two aspects! However, it should be able to realize a more controllable (and on average shorter) lead times at the shop floor which influences the performance to the customer in a positive way.
2.2 Action
Research
Company X
1. a pre-step – to understand context and purpose;
2. six main steps – to gather, feedback and analyze data, and to plan, implement and evaluate action;
3. a meta-step to monitor.
Figure 9 Action research cycle (Coughlan, 2002)
After the Context & purpose have been discussed (Chapter 3) the six main steps (gather, feedback and analyze data, and to plan, implement and evaluate action) will be performed again and again to solve problems and increase the benefits of the Takt-system. Data will be gathered by the Enterprise Resource Planning (ERP) system called Baan in which a lot of the production and product data is kept. Besides the ERP system, information is also gathered by interviews, observations of the primary process, attending project meetings and (informal) meetings with employees of the organization. The initial performance will be measured and analyzed by generating data by using forms and ConWIP cards (see Figure 29 CONWIP cards and forms, page 38). A schedule has initially been made to introduce the workload control system in 3 stages (introduction of cards, lowering WIP and screen introduction). The implementation of the workload control system will follow these stages. A weekly evaluation by the project team monitors the progress of the introduction of the workload control system. In this way accurate steering should be possible. At the end the new situation will be
compared to the initial situation.
2.3 Recent
studies
Company X
2.4
Recent results of TAKT at MACHINE COLLECTION-3
As mentioned above MACHINE COLLECTION-3 (Type3) started already working with the Takt-system. The goal was to decrease the lead time and to increase the on-time performance. The effects on these variables were as follows:
• The OTR performance at the Type3 increased from 55% in 2007 to an average of 80% in 2008 and is still increasing.
• The lead time at this line decreased from an average 11 days in 2007 to a level of just below 2 days in May 2008.
A visual representation of these performance indicators is represented in the Figure 10 & 10 below.
Figure 10 OTR Type3 Figure 11 Lead time Type3
The results of Takt at MACHINE COLLECTION-3 and the earlier mentioned studies support the implementation at MACHINE COLLECTION-2. The recent implementation at MACHINE
Company X
2.5 Thesis
outline
Figure 12 represents the outline of this thesis. In the following chapter the context and initial state is described based on the aspects from the conceptual model (page 13); People, Process and Product. In part 2 of this thesis the change process will be described. This will also be based on the 3 P’s. Chapter 5 will take a closer look at the chronological report and will reflect the process.
After the change process has been described and reflected, the results and evaluation will be discussed in part III.
Describe Monitoring by AR Ch. 1 Introduction Ch. 2 Research outline Ch. 3 Production characteristics & Initial state PART II Change Ch. 9 Results Ch. 10 Evaluation Ch. 4 - 7 Chronological report Ch. 8 Analysis people
3.1 people 3.2 Process 3.3 Product
PART I Introduction and
initial state
PART III Conclusion
Company X
3 Production characteristics of MACHINE COLLECTION-2
This chapter will answer the first sub question “What are the initial characteristics of process and product in MACHINE COLLECTION-2 and what does it mean for WLC?”. It is important to know the characteristics of MACHINE COLLECTION-2 because these could effect the success of a Takt-system at MACHINE COLLECTION-2.
Matthias Kauw and Justin van Loon did research on which product flows could be identified in MACHINE COLLECTION-2. Figure 13 below shows their findings. The 4 digit numbers in the figure represents the machines. Appendix 1 “Task number and corresponding machine” shows the corresponding machines to these numbers.
Company X
The 4 identified production flows have been used in Table 14 below. The operations have been rearranged to give a more clear view about the machine groups. As shown in the table below, flow 1&2 are almost completely independent of flow 3&4, only operation B (“ontvetten”) makes a connection between the 2 pairs of mainstreams.
Table 14 production flows
flow / Operation A E L D1 D2 N I H J K B C F G Name Dra a ien Dra a ien Bankwe rken
Zagen Zagen Dra
a ien Buigen Fre z en CNC F rez e n C o nv Boren/Ta ppe n Ontv etten Solderen Ponse n Tromm e len 1 1 2 3 2 1 2 3 4 5 3 1 2 3 4 (A) 4 (B) 4 (C) 4 (D) 4 (E) 1 1 1 1 1 2 2 2 3 3 2 4 2 3 4 3 5
The numbers in the cells represent the operation steps. There are 2 (flow 4B) till 5 (flow 2& 4D) operation steps for each flow. Flow 3&4 are flows that are almost completely independent of flow 1 & 2.
The management of CXS has decided to introduce the Takt-system first at flow 3&4, which contains 77% of all MACHINE COLLECTION-2 orders, because of the very long throughput times of the orders of flow 1 & 2. After implementation of Takt at flow 3&4 management will decide whether or not and how to handle orders of stream 1&2. The result will be the
Company X
Company X
<< Figure deleted>>
Figure 15 CXS after introduction of Takt in production flow 3 end 4 of MACHINE COLLECTION-2
3.1
Work order release initial state
Bokhorst, Slomp (2006) wrote: “The work order release function should release orders in conformity with material management and workload control. However, there should also be alertness to the actual status on the shop floor (e.g. ill people and/or machine breakdown). Decisions on the necessary measurements can be taken in regular meetings usually held weekly. Examples of measurements are the hiring of temporary workers and the decision of overtime work for one or more days. A planning officer who works in the manufacturing department performs the work order release. The meetings are attended by the planning officer, the operation manager, the foremen of the Production Units and the shipping manager”.13 The order release in the initial situation is almost the same as illustrated above, only the task of the shipping manager is not in line with the initial situation at Company X Y.
Company X
Figure 16 representation current acceptance and order release 14
3.2
Product, Process and Performance initial state
The products of MACHINE COLLECTION-2 can be divided into 4 flows (Table 14). Justin van Loon en Matthias Kauw (2008) investigated which flows could be identified. 78% of all orders followed
production flow 3&4. Production flows 3&4 have, compared to stream 1 and 2, the smallest average production time, (3 hours versus 8 hours for stream 1 and 37 hours for stream 2). The average number of operations for production flow 1, 3&4 is 2 steps. For production flow 2 the average number of operations is 5 steps.
In the initial state planners plan which orders have to be produced. Planners are nesting orders so that the production is as efficient as possible. In case of too much work, orders are outsourced to external parties. For the work floor it is not clear in which sequence orders should be started. They only take care that emergency orders are handled first. Nobody knows exactly when an order will leave the department. Extreme lead times are not registered at order level, only the average production lead time (4,5 days, see page 11) is known, which is based on measurement by the ERP system called Baan.
Company X
3.3
Comparing MACHINE COLLECTION-2 and MACHINE
COLLECTION-3
As already noticed MACHINE COLLECTION-3 already uses the Takt-system. The management is intended to implement the Takt-system also in MACHINE COLLECTION-2. An copy of MACHINE COLLECTION-3 might not fit to MACHINE COLLECTION-2 as the characteristics of the MACHINE COLLECTION’s are not the same. By comparing the MACHINE COLLECTION’s the differences between the MACHINE COLLECTION’s will appear. These differences could be used to adjust the Takt-system of MACHINE COLLECTION3 towards a system that fits the characteristics of MACHINE COLLECTION-2.
As mentioned in chapter 2.3 two other students supported the introduction of the Takt-system at MACHINE COLLECTION-3. The Logistics manager is very enthusiastic about the results of the implementation (see 2.4). Characteristics of MACHINE COLLECTION-2 where mentioned already in the beginning of this chapter. Some of the characteristics of MACHINE COLLECTION-3 and
differences compared to MACHINE COLLECTION-2 are mentioned in Table 17.
Table 17 differences between MACHINE COLLECTION-3 and MACHINE COLLECTION-2
MACHINE COLLECTION-3 (Type3) MACHINE COLLECTION-2 (Type 2)
1 main routing 4 main routings
Starting operation is bottleneck Bottleneck shifts between operations Number of operations = ? Number of operations = 2,85
change over time = relatively small change over time can be very long (up to 6 hours for milling machines)
Orders within MACHINE COLLECTION-3 have more or less the same production lead time. Average lead time = 1day
Order lead times vary a lot
Average production lead time = 4,5 days Lead time is lower Lead time is higher
From a technological point of view are the operations in MACHINE COLLECTION-3 easier.
From a technological point of view are the operations in MACHINE COLLECTION-2 harder (MX40 and Deckel) .
In their report Kauw and van Loon (2008) defined the differences and the similarities as follows: Table 18 Similarities and differences between MACHINE COLLECTION-3 and MACHINE COLLECTION-2
Similarities between MACHINE COLLECTION-2 and MACHINE COLLECTION-3 are:
Differences between MACHINE COLLECTION-2 and MACHINE COLLECTION-3 are:
A strong variation in the sequence of operations Within MACHINE COLLECTION-2 are several production flows
Company X
MACHINE COLLECTION-2 A strong variation in order size
One of the differences is that MACHINE COLLECTION-2 contains 4 production flows. It might not be wise to use one WLC system to handle all production flows as the different flows have (very) different lead times. In the Takt-system orders have to be finished within a specified time limit. This time limit might be reasonable for one/several flow(s) but does not have to be reasonable for all flows. A too high time limit would not realise optimal lead times while too low time limits would result in too much urgent orders.
It is easier to handle bottlenecks if there is much flexibility in machine capacity. There is more capacity flexibility in MACHINE COLLECTION-3 compared to MACHINE COLLECTION-2. This is due to less complex operations. When operators could operate more machines, flexibility of the capacity of machines increases. On average more education is needed in MACHINE COLLECTION-2 (compared to MACHINE COLLECTION-3) to be able to work with a machine. It is therefore harder to realise a multi skilled workforce. Therefore increasing the availability of machines by increasing the education of personnel is harder to realise in MACHINE COLLECTION-2 compared to MACHINE COLLECTION-3. Another difference is that in MACHINE COLLECTION-3 ca. 95% of all orders start at Type 4. The planner at MACHINE COLLECTION-3 is responsible for filling this buffer with “Type 4 orders” for 2,5 days. Because there is only one buffer from which orders are started, the planner only has to take care that this buffer is filled. If this buffer is filled the planner does not have to take care whether or not a machine is overloaded or starving because (almost) all orders start at the same machine and come from the same buffer.
Only the Type 4 machine (P) has to be protected from starving. If there are only Type 4 orders available then it does not matter what the planner releases (he can only release Type 4 orders). So it can be said (and it is said) that the planner can “release orders at random”. Figure 19 shows the situation of MACHINE COLLECTION-3.
P o2 o2 o2 o2 o2
Takt
out
Takt in buffer
one
type of orders
TAKT SCREEN
Company X
Because of the very positive results at MACHINE COLLECTION-3, TAKT is also introduced at MACHINE COLLECTION-2. But there is a difference: MACHINE COLLECTION-2 has several start operations. Therefore the rule as used in MACHINE COLLECTION-3 to release orders at random might not be usable in MACHINE COLLECTION-2.
Investigation the starting operations (within MACHINE COLLECTION-2) of the orders over the year 2007 lead to result as is shown in table.
Table 20 Starting operation
task Machine orders percentage 6441 SAWING KASTO 1882 37,0% 6403 LEADWELL 744 14,6% 6442 SAWING EISELE 577 11,3% 6410 PUMA 240 570 11,2% 6443 SAWING ALTEND 324 6,4% 6890 ONTVETTEN 300 5,9% 6401 CAZANEUVE 179 3,5% 6409 TNM 42 108 2,1% 6421 HURON 95 1,9% 6562 BANKWERKEN 74 1,5%
As can be seen 54,7% of all orders start at an sawing machine (Kasto 37%, Eisele 11,3% and Altend 6,4%). Summarizing the percentages will result in 95,4%. The last 4,6% starting operations are divided over 13 machines. The situation with several start operations (for example A-E) in MACHINE COLLECTION-2 is visualized in Figure 21 below.
Figure 21 release of order at MACHINE COLLECTION-2 several starting operations. If the orders will be released at random and not looking at start operation (cause MACHINE
Company X
second operation for another order. Actually the planner has to maintain several buffers, as can be seen in Figure 22 below.
Figure 22 suggested order release MACHINE COLLECTION-2
The buffer in front of each starting operation could protect the operations from starving. Overloading can also be protected by comparing the wanted (maximum) buffer size by the actual buffer size.
3.4
Organization initial state
One of the components which influences the workload control system are the people. Managers, supervisors, planners and operators should be willing to support the introduction of the Takt-system. A lot has been written about change. People have a big influence on the success of the change process. Chapter 4 describes the change process.
3.5
Conclusion initial state
The management of CXS is intended to introduce a Takt-system in MACHINE COLLECTION-2 because of the positive results of the Takt-system in MACHINE COLLECTION-3 (see 2.4). The chapter was aimed to give insight in the process and product characteristics to which the WLC system
should fit (see Figure 23).
Company X
The management wants to use the Takt-system as “the way” to realise WLC. Due to the differences in characteristics between MACHINE COLLECTION-3 and MACHINE COLLECTION-2 the Takt- system of MACHINE COLLECTION-3 has to be adjusted to be able to use it in MACHINE COLLECTION-2. It is therefore needed to anwer the first part of the first subquestion: “What are the initial characteristics of process and product in MACHINE COLLECTION-2?”.
One of the aspects which should be taken into account is the fact that MACHINE COLLECTION-3 has only one production flow. In this flow almost all orders (90%) are starting at the Type 4 Machine. This machine is also the bottleneck in MACHINE COLLECTION-3. In MACHINE COLLECTION-2 several production flows are present. Takt will first be introduced to flow 3&4 which are responsible for 77% of the orders. Most orders (54%) in MACHINE COLLECTION-2 start at a sawing machine. However still 46% starts at another machine. The rule as used in MACHINE COLLECTION-3, to release every day a specified number of random orders, might not work. In MACHINE COLLECTION-2 this rule might result in overloading machines while other machines are starving. Another important difference is that in MACHINE COLLECTION-2 starting machines are also loaded by orders that already finished their first operation.
Due to these two differences it can be concluded that MACHINE COLLECTION-2 is more complex then MACHINE COLLECTION-3.
The second part of the first research question is “(…and what does it (the initial characteristics of process and product in MACHINE COLLECTION-2) mean for WLC?”. The system in MACHINE COLLECTION-2 will be derived from the system used in MACHINE COLLECTION-3 and will therefore be mostly the same. However due to the differences the system has to be adjusted to fit to the
situation of MACHINE COLLECTION-2.
Because of the numerous starting machines the rule of MACHINE COLLECTION-3 to release orders at random is not usable in MACHINE COLLECTION-2. The planner has to take into account the load on the several starting machines. This could be done by adjusting the system. When the current load on these machines is known, overloading and starving can be protected.
Company X
PART II
Company X
4 Change
process
The second sub question is “How to organize change?“. To answer this question the change process will be compared to literature. Therefore change literature will be discussed in this chapter after which the change process will be described and analysed in the following chapters.
4.1
Theory about change
The article “Successful Change Management” by Oakland & Tanner (2007) provides a review of the existing change literature. The literature review included work by Beer, Carnall, Collins, Eisenhardt, Kotter, Nohria, Porras, Senge and Turner. In addition senior management of 28 organisations were interviewed to gain their insights on how to manage change successfully. They were asked what practises significantly helped or hindered the change programme. The literature review as well as the interviews have been used to define several categories which highly influence the performance of a change process. These categories are commitment, Need for change, Management and execution. The insight of senior management as well as the literature review has been assigned to one of the four categories.
Need for change / communication of the goal
• A ‘vision’ for change must be embraced throughout all levels of the organisation, especially by those functional and middle-level managers affected by the change.
• There tend to be strategic ‘stimuli’ ranging from financial pressures, continued market leaderships, customer dissatisfaction and/or organization inefficiencies that trigger business process change.
• Measurement is key to success. A well-defined process management approach should include a documented methodology of change, and use objective and quantified metrics showing the value of change.
• Data-led analysis (hard facts) is an important aspect.
• Set stretch goals. Goals should be set a little higher than what the team believes they can accomplish.
• General issues based on resistance to change and project management issues i.e. silo thinking, delays etc. can hinder change.
Commitment
Company X
• Bottom-up or empowered implementation is vital while support from the top is critical, actual implementation should be carried out from the bottom-up. The idea of empowerment is to push decisions down to where the work is actually done.
• Communication and maintaining stakeholder support is critical and progress should be tracked and publicised.
• Changes in the organisation, e.g. re-design, departure of Managing Director can hinder change.
Management
• Project planning and management are critical.
• An important ingredient is leadership from the top, together with an atmosphere of open communication, participation, and cross training.
• Disciplined project management is important. • Clear accountability and goals.
Execution
• Execution is the real difference between success and failure. Real change will not happen without a plan for change and aggressive execution of that plan. Execution fails in many cases because organisations are not willing to dedicate resources, time, and energy to the effort.
The project management should be aware of the aspects noticed above. Based on the literature of Oakland & Tanner it can be suggested that a successful change process should answer the following questions with “yes”.
• Is there a good reason to change? • Is there sufficient commitment? • Is the project managed well?
• Are there sufficient resources mobilized?
In addition to the literature noticed above, management could also use a model to focus their activities on specific business results.The “ADKAR” model is an example of such a model. It can be used as a tool to determine if change management activities like communications and training are having the desired results during change. The model has its origins in aligning traditional change management activities to a given result or goal. The ADKAR model suggests that change requires managing five key goals that form the basis of the ADKAR model these are15:
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3. Knowledge of how to change (and what the change looks like) 4. Ability to implement the change on a day-to-day basis
5. Reinforcementto keep the change in place
Each stage within the change process can be reflected to the model and the literature noticed above. In this research the process towards a Takt-system will be compared with the success factors from literature and the ADKAR model. Change happens on two dimensions: the business dimension (vertical axis) and the people dimension (horizontal axis). Successful change happens when both dimensions of change occur simultaneously.
Figure 24 Implementation process should be in line with change for the employees.
The usage of the success factors according to Oakland & Stephen Tanner can be combined with the phases of the ADKAR model. The table below will be filled while describing the change process. At the end of chapter 8 a filled in version of the table below will give insight in which success factors
supported a specific phase during the change process.
Table 25 success factor – ADKAR matrix.
A D K A R
Need for change / communication of the goal
A ‘vision’ for change must be embraced throughout all levels of the organisation,
especially by those functional and middle-level managers affected by the change. There tend to be strategic ‘stimuli’ ranging from financial pressures, continued
market leaderships, customer dissatisfaction and/or organization inefficiencies that
trigger business process change. Measurement is key to success. A well defined process management approach
should include a documented methodology of change, and use of objectives and
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General issues based on resistance to change and project management issues i.e.
silo thinking, delays etc. can hinder change.
Commitment
The role of the sponsor is pivotal in developing support for the change. Top management commitment is important. Cross functional teams with high performers and the right skills. Bottom-up or empowered implementation is vital while support from the top is
critical, actual implementation should be carried out from the bottom-up. The idea of
empowerment is to push decisions down to where the work is actually done. Communication and maintaining stakeholder support is critical and progress should
be tracked and publicised.
Changes in the organisation, e.g. re-design, departure of Managing Director can
hinder change.
Management
Project planning and management are critical. An important ingredient is leadership from the top, together with an atmosphere of
open communication, participation, and cross training. Disciplined project management is important.
Clear accountability and goals.
Execution
Execution is the real difference between success and failure. Real change will not happen without a plan for change and aggressive execution of that plan. Execution fails in many cases because organisations are not willing to dedicate resources,
time, and energy to the effort.
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5 Creating
Awareness
The following chapters will give insight how the organization and the change process are influencing each other during the implementation of the workload control system at MACHINE COLLECTION-2. This to answer the second sub question “How to organize change?”.
The situation before any changes were made, was described in the previous chapter. This chapter will describe the change process. A planning has been made for the whole project. Dates when stages had to be finished where not made. The planning was roughly divided in the following stages:
0. Pre phase to create awareness. 1. Introduction cards
2. Constant WIP
3. Constant WIP & Screen introduction 4. Constant WIP & Order sequence
Only the stages 0 up to 3 will be described in this thesis. This because stage 4 is not realised till the moment this thesis had been written. In other words: Up to the moment the screen is operational and operators are reacting to the information (order lead times) given on the screen. This chapter will continue discussing the creation of awareness. Chapter 6 will handle the Introduction cards and WIP. Chapter 7 will discuss the Screen introduction. Both chapters discuss the continuous action-reaction loop between people and the introduction process which is illustrated in Figure 26.
Figure 26 Continuous action-reaction loop between people en the WLC implementation process
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change is needed, the reaction of employees can (based on the awareness) probably be different. To be able to make the Takt-system a success, the creation of awareness is an important aspect.There has been written a lot about awareness. A lot of success factors, noticed in Table 25 above, might be important in the awareness phase of the ADKAR model. Several people are involved during the change process; managers, planners, supervisors and last but not least the operators. To inform the operators about the goal and progress of the project, every week on Thursday there was a meeting. On May 28, the operators where informed about the current performance, the goal of the project and the first phase of the change process (the usage of the ConWIP-cards (see next paragraph)).
Operators reacted neutrally, “they would see what would happen”. Several groups were formed who had to support the introduction of Takt. These groups were IT, Logistics, Communication and Finance. These groups consist of employees such as planners and supervisors and were managed by the logistic manager. In this way the medium staff was informed about the progress of the change process. Operators were not involved in these meetings. They were only informed in the weekly meetings and by informal conversations at the work floor.
The goal of the Takt-system was clearly communicated to all stakeholders. But not everyone was persuaded of the advantages. Especially the supervisor and planner wondered whether something simple as using cards would really help to increase the performance of MACHINE COLLECTION-2. Showing the hard results of MACHINE COLLECTION-3 did not change their opinion.The results of MACHINE COLLECTION-3 were not valuable according to them because MACHINE COLLECTION-2 was very different (in characteristics) compared to MACHINE COLLECTION-3.
There can be concluded that the awareness phase contained several success factors:
- The vision for change was communicated well (what the effect would be after change) - The current performance was shown in hard numbers and showed the possibility to
increase the current performance.
- The goals as OTR increase and LT decrease were seen as hard but realisable. - Top management commitment
- Cross functional teams with high performers and the right skills. - Project planning and management are critical.
- Disciplined project management is important.
In addition, there are some aspects that could have been given more attention:
- The stimuli (why to change) that triggered the change process was not communicated very well.
- The role of the sponsor is pivotal in developing support for the change. The logistic manager was very enthusiastic but supervisors and planners were not 100% convinced about the system.
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- Communication and maintaining stakeholder support is critical and progress should be tracked and publicised. There was a lot of communication with all stakeholders but maintaining stakeholder support could have been given more attention. The support of some stakeholders was not optimal probably due to the fact that they were not
convinced about the success the Takt-system would bring.
- An important ingredient is leadership from the top, together with an atmosphere of open communication, participation, and cross training. There was enough leadership from the top and middle management had the change to participate. Operators could have been involved more.
- Clear accountability and goals. It was not completely clear communicated who was responsible for realising the success of the Takt-system.
A overview of the success factors from literature and how they were used in the awareness phase are noticed in Table 27.
Table 27 success factor – Awareness matrix.
Awareness
Need for change / communication of the goal Score Comment
A ‘vision’ for change must be embraced throughout all levels of the organisation, especially by those functional and middle-level managers affected by the change.
+ Management was clearly communicating the successes of Takt in MACHINE COLLECTION-3 and the intention to introduce it at MACHINE COLLECTION-2 There tend to be strategic ‘stimuli’ ranging from financial pressures,
continued market leaderships, customer dissatisfaction and/or organization inefficiencies that trigger business process change.
0 Willing to increase performance but there was no pressure to change.
Making measurements is a key to success. A well-defined process management approach should include a documented methodology of change, and use of objective and quantified metrics showing the value of change.
+ Realised
Data-led analysis (hard facts) is an important aspect. ++ Graphs about current performance are available. Set stretch goals. Goals should be set a little higher than what the team
believes they can accomplish. ++ Goals were clearly communicated General issues based on resistance to change and project management
issues i.e. silo thinking, delays etc. can hinder change.
Commitment
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success Takt should bring.
Top management commitment is important. ++ Realised Cross functional teams with high performers and the right skills. + Realised Bottom-up or empowered implementation is vital while support from the
top is critical, actual implementation should be carried out from the bottom-up. The idea of empowerment is to push decisions down to where the work is actually done.
- Top management was committed but lower management were less committed. Decisions were made by the top. Implementation was top-down oriented Communication and maintaining stakeholder support is critical and
progress should be tracked and publicised. -- Support stakeholders below the from top was not optimal. Changes in the organisation, e.g. redesign, departure of Managing
Director can hinder change.
Management
Project planning and management are critical. ++ Management was investing a lot of time to make the project a success.
An important ingredient is leadership from the top, together with an
atmosphere of open communication, participation, and cross training. 0 Mostly top down communication. Operators were not actively participating. Disciplined project management is important. ++ Management was
investing a lot of time to make the project a success.
Clear accountability and goals. - It was not clear who was responsible for (parts of) the project.
Execution
Execution is the real difference between success and failure. Real change will not happen without a plan for change and aggressive execution of that plan. Execution fails in many cases because organisations are not willing to dedicate resources, time, and energy to the effort.
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6 Introduction
cards
This chapter describes an important part of the change process: The introduction of “ConWIP” cards. In chronological order the usage of ConWIP cards is discussed. Topics that will be noticed are
• Instructions about the usage of cards • Problems concerned the usage of cards • Lead time results
• WIP results • Takt time calculation • Questions of operators • Responsibilities
Since May 30 2008, operators had to add a CONWIP card when they started working at an order of production flow 3 or 4. Operators were asked to fill in date, time and order number when they start production and when the order leaves MACHINE COLLECTION-2. It was not clear to the operators which benefits the Takt-system would bring them. There was actually no reason why they should or should not be willing to use the cards. In MACHINE COLLECTION-2 orders are pushed from operation to operation. As in Kanban, the amount of orders moving through the process remains constant as determined by the number of cards in the system. The entire amount of WIP in the process is constrained by the number of cards. To be sure that introducing the ConWIP cards would not have an effect on the initial WIP it was ensured that there would always be enough cards available.
When orders left MACHINE COLLECTION-2 the cards where removed from the product and sent back to the start place.
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<< removed>>
Figure 28 visual representation of the usage of cards for flow 3&4
As already mentioned in chapter 3 the introduction of CONWIP cards started at stream 3 & 4 which handles 78% of all orders at MACHINE COLLECTION-2. The only interaction between stream 3&4 and 1&2 is the fat removing operation (“ontvetten”), but as this operation was not considered to be a bottleneck this should not be a problem.
When a new order is started (e.g. start sawing) a card has to be added to the order and the date, card number and order number have to be registered on a form (see Figure 29 and 23).
Figure 29 CONWIP cards and forms Figure 30 CONWIP cards added to orders
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The maximum number of work in process (WIP) is 120 orders (because there are 120 cards) by counting the number of cards the level of WIP is expected to be calculated easily (WIP=120-number of cards in the box).
In a recent research project students identified 4 main flows (see chapter 3). To make clear when an order is part of flow 3 or 4 an table was made and the machines which where part of flow 3 or 4 where highlighted. Operators should only put a CONWIP card in the order when the machine is highlighted in the list. The list is shown in Figure 31.
Task Name Task Name
6401 REMOVED 6502 REMOVED 6402 REMOVED 6523 REMOVED 6403 REMOVED 6525 REMOVED 6404 REMOVED (flow 1) 6552 REMOVED 6407 REMOVED (flow 1) 6562 REMOVED 6408 REMOVED 6563 REMOVED 6409 REMOVED (flow 2) 6777 REMOVED 6410 REMOVED 6803 REMOVED 6411 TT 1800 SY 1 (flow 1) 6807 REMOVED 6421 REMOVED 6833 REMOVED 6426 REMOVED 6840 REMOVED 6441 REMOVED 6841 REMOVED 6442 REMOVED 6850 REMOVED 6443 REMOVED 6882 REMOVED 6451 REMOVED 6890 REMOVED 6463 REMOVED 6891 REMOVED 6471 REMOVED 6892 REMOVED
Figure 31 add a conWIP card list 30-5-2008
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After using the cards for one week the first results became available. The Lead time of finished orders (in days) as well as the WIP were measured. The measurements till the 6th of June are mentioned below (Figure 32). It should be noticed that only orders which are finished are mentioned in the lead-time graph.
Figure 32 Lead-time orders after one week
“Old” orders where still in the system and were slowly replaced by orders with a card. Because most orders (98%) have a lead time <15 days, after 15 days most of the “old” orders should have left the system. Therefore, a correct measurement of the WIP should be available 15 days after starting introducing ConWIP cards.
During the first week of using cards, the first problems occurred. Examples of these (little) problems are:
• an order number that was not written down correctly on the form
• orders that were not written down on the form after an order was finished • 12 hour notation instead of 24 hour notation
In the weekly meeting on Thursday operators were informed about the goal, the problems so far and the successes. In the 2nd meeting (week23) it became clear that is was not always clear when to add a card. The list with starting operations was not referenced often enough. Management referenced the list again and decided to add some more machines. In this way the procedure was made easier. Only 4 machines which belong to production flow 1 and 2 where kept out of the measurement. At week 24 the list with machines where to add a card was adjusted. Only when the operation starts at the TNM 42, TT1500 or TT1800 no card had to be added. The list changed into the one below (Figure 33):
LT sawing and soldering
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Task Name Task Name
6401 REMOVED 6502 REMOVED 6402 REMOVED 6523 REMOVED 6403 REMOVED 6525 REMOVED 6404 REMOVED (flow 1) 6552 REMOVED 6407 REMOVED (flow 1) 6562 REMOVED 6408 REMOVED 6563 REMOVED 6409 REMOVED (flow 2) 6777 REMOVED 6410 REMOVED 6803 REMOVED 6411 REMOVED (flow 1) 6807 REMOVED 6421 REMOVED 6833 REMOVED 6426 REMOVED 6840 REMOVED 6441 REMOVED 6841 REMOVED 6442 REMOVED 6850 REMOVED 6443 REMOVED 6882 REMOVED 6451 REMOVED 6890 REMOVED 6463 REMOVED 6891 REMOVED 6471 REMOVED 6892 REMOVED
Figure 33 add a ConWIP card list 12-6-2008
The level of WIP increased during week 25 (see Figure 34). This might be due to the work instructions which had been changed the week before.
Figure 34 WIP increase after change of work instructions
There also became more insight in the lead time of started orders. The average time between an order was started and the moment is was ready to ship was 3 days for sawing and less then 3 hours for soldering orders. Figure 35 shows the measurements till the 20th of June.
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Figure 35 Lead time orders.
The introduction of cards can be seen as stage 1 in the AR model. The observed effects on the behaviour (stage 2) of people can be seen as the “data feedback stage” of the AR model. During the introduction of cards the operators were enthusiast and did their best to make the first stage to a success. Planners and supervisors were critical on the Takt-system. They thought that the efficiency would drop, this due to a lower WIP and therefore less possibilities to combine orders. This would consequently create more machine changeovers. Their opinion was therefore that Takt would not be a good idea. Besides that, it was not clear which benefits the system would bring to the operators. The only reason why they would be willing to change was because the logistic manager asked them. To show the importance of the Takt introduction the production manager of Averagesystems was asked to speak on the weekly appointment. On 19th of June he showed the importance of lead time
decrease.
LT sawing and soldering
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In Week 26 (28th june) the longest lead times in the WIP measurement where analysed. WIP was determined by comparing the start forms with the finished forms. Microsoft Excel was used to make this comparison easier. To measure the WIP, the start- and finish forms where compared to find out whether or not a started order was finished. When the order was finished it was not used in the WIP measurement. When it was not finished the order was taken into account in the WIP measurement. By comparing the WIP orders with the ERP system (Baan) it appeared that some orders where already finished but not registered as finished on the forms. The measurement had therefore to be adjusted. To be able to give a representative view it was decided to only show the finished orders in the lead times graphs in this thesis.
An example of orders that where not finished according to forms but where according to the ERP system (BAAN) can be seen in Table 37 below.
Table 37 analysis long lead times
Card # Order Start date Lead time Comment
59 665965 4-jun 24 days WIP (correctly registered) 66 666100 5-jun 23 days FINISHED (not registered)
16 666086 11-jun 17 days WIP (machine failure & correctly registered) 18 666134 11-jun 17 days FINISHED (not registered)
26 666071 12-jun 16 days FINISHED (not registered) 50 845740 16-jun 12 days WIP (correctly registered) 62 883912 16-jun 12 days FINISHED (not registered) 80 883937 19-jun 9 days WIP (correctly registered) 2 666197 19-jun 9 days WIP (correctly registered) 3 666095 20-jun 8 days WIP (correctly registered) 9 845771 20-jun 8 days WIP (correctly registered)
8 845789 20-jun 8 days FINISHED (to Galvano & not registered)
One of the reasons for long lead times might be that operators are continually working on high priority orders. As a consequence other orders, such as those in Table 37, did not get enough attention. In addition, it might be that the orders with high lead times are simply orders that contain annoying operations.
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Since week 28 10-7 the usage of cards decreased. A lot of orders on the work floor did not have a card. Attention was given to this problem in the weekly meeting with the operators. Noticing this problem had a positive effect; as can be seen in Figure 38 the WIP increased a lot since the meeting.
Figure 38 WIP Week 28 2008
Since the beginning of using cards there was decided to have two places where cards where
collected. The only reason for doing so was to reduce walking distances. To be able to show a correct overall performance of MACHINE COLLECTION-2 the measurements of both places needs to be combined. Since week 29 the measurements where combined. The lead time of orders in MACHINE COLLECTION-2 is shown in Figure 39 and 39. As can be seen most orders are finished within several days. A relatively small percentage of the orders has quite long lead times.
DLT van gestarte orders
0 20 40 60 80 100 120 140 160 < 1 dag < 2 dag < 3 dag < 4 dag < 5 dag < 6 dag < 7 dag < 8 dag < 9 dag < 10 dag < 11 dag < 12 dag < 13 dag < 14 dag < 15 dag < 16 dag >16 dag duur aa n ta l Zagen Solderen
doorlooptijd van gestarte orders
0% 20% 40% 60% 80% 100% 120% < 1 dag < 2 dag < 3 dag < 4 dag < 5 dag < 6 dag < 7 dag < 8 dag < 9 dag < 10 dag < 11 dag < 12 dag < 13 dag < 14 dag < 15 dag < 16 dag >16 dag
Saw ing Soldering
Figure 39 number of orders / lead time Figure 40 cumulative percentage Lead times The lead time of the orders that got their card from sawing had an average of 4,1 days, almost all soldering orders had a lead time of <1 day (98%).
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soldering is shown in the Figure 41 below. In MACHINE COLLECTION-3 80% of all orders is finished within the time limit. When this performance should be realized by MACHINE COLLECTION-2 the time limit should be 4 days. This because for MACHINE COLLECTION-2 80% of the orders is finished within 4 days.
Figure 41 Lead time orders (sawing and soldering combined) (2008/7/18)
After about 1 month of using cards it became clear that the Takt screen would become operational at August 11. This because the planner and/or the production manager had vacation until this time. The project team decided that both persons should be present at the introduction of the screen. To prevent the project from slowing down (wait one month to introduction of the screen), the production manager of CXS, a (replacing) supervisor and a (replacing) planner kept an appointment on the July 15. The results of the measured period (May till mid of July) where shown in this meeting. The showed work in progress list contained a lot of orders that where for a long time at MACHINE COLLECTION-2. These orders should be finished soon. The supervisor already used a list with priority 100 orders. In
MACHINE COLLECTION-3 orders got priority when they were to long in the system. 80% was finished in time. In MACHINE COLLECTION-2 80% was finished within 4 days. When applying the same priority rule to MACHINE COLLECTION-2 as in MACHINE COLLECTION-3 orders should get priority when they have a lead time over 4 days (which is 4*18=72 hours) As can be seen in the lead time column (“Throughput time”) in Figure 42, 10 of the 19 orders on this list had a lead time of more than 72 hours. These orders should have priority based on the performance criteria that 80% of all orders had to be finished within 4days.
LT Sawing and Soldering
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Figure 42 Priority (code 100) list supervisors.
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Figure 43 increase in priority orders.
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The number of orders finished was on average about 331/30 days (including Saturdays and Sundays). Figure 44 shows the moving average of the finished orders over the last 30 days.
250 270 290 310 330 350 27-6 -200 8 28-6 -200 8 29-6 -200 8 30-6 -200 8 1- 7-200 8 2- 7-200 8 3- 7-200 8 4- 7-200 8 5- 7-200 8 6- 7-200 8 7- 7-200 8 8- 7-200 8 9- 7-200 8 10 -7-2008 11 -7-2008 12 -7-2008 13-7 -200 8 14-7 -200 8 15-7 -200 8 16 -7-2008 17 -7-2008 18 -7-2008 19 -7-2008 20 -7-2008 21 -7-2008
Figure 44 Finished orders moving average over 30 days.
If assumed that the number of produced orders is equal to the desired number of produced orders then 331 orders/30 days should be produced which is about 11 orders a day (including Saturdays and Sundays). So, on average 77 orders are produced in 1 week, and as a consequence 77/5=15,4 orders/workday.
MACHINE COLLECTION-2 works with a 2 shift (Monday – Thursday 6.00-15:00 and 15:00-24:00) (Friday 6.00-15:00 and 15:00-19:00). Each shift has 0,5 hour break. Therefore 80 hours are available in one week as can be seen in the calculation below.
Monday - Thursday 6.00-24.00 =18 hours - 1 hour break 4*17= 68hours Friday 6.00-19.00 =13 hours - 1 hour break 1*12= 12hours
Total / week 80 hours
Takt time therefore would be 80hours / 77orders = 1.04 hours which is about 62 minutes.
The Takt screen in MACHINE COLLECTION-3 has 60 positions (=maximum WIP) on average every Takt time an order should leave the screen. When having 60 positions an order should leave the screen after 60*Takt time. When the Takt time is 62 minutes an orders should leave the department within 60*62 minutes = 62 hours.
Because the production time is 17 hours on Monday until Thursday and 12 hours on Friday the production schedule should look like as follows:
Table 45 Production schedule
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Tuesday 17 62 minutes (1.04 hour) 16.4 Wednesday 17 62 minutes (1.04 hour) 16.4 Thursday 17 62 minutes (1.04 hour) 16.4 Friday 12 62 minutes (1.04 hour) 11.6
Total 80 62 minutes (1.04 hour) 77,2
In the meeting in week 30, attention was given to the correctly usage of cards. This because the correctly usage of cards decreased. The lack of using cards can be seen in the graph “WIP week 30 (2008/7/25)” (Figure 47), in which the WIP decreased since 2008/7/11. Attention was given to these problems on the weekly meeting as can be seen in Figure 46 below.
Figure 46 problems week 30 correct usage of cards As can be seen in Figure 46 problems that occurred were:
• Some products were produced without an order. • Some orders did not have a ConWIP card.
• It was sometimes forgotten to remove the ConWIP card from orders that were ready to ship. • Sometimes it was forgotten to add a ConWIP card when orders were taken into production. All orders that should have a card but did not have one yet, got a card and were added to the
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Figure 47 WIP week 30 (25-7-2008)
To ensure the usage of cards it was decided to make the supervisor responsible. This because he is already responsible for the operators and the operators should add the cards. The supervisor would get a financial award when the Takt-system would become a success. By doing this he was motivated to make the usage of the cards a success. This step can be seen as creating a desire to change. When the supervisor wants to realise his financial award, he has to ensure that the cards are used correctly.
2 weeks later (Week 32) there were still orders without a card. Besides that, some operators did not came to the weekly meeting. After the meeting the operators who where not at the meeting where asked why they believe the meeting is meaningless. They suggested that the questions where not answered by the management. An oral survey led to the following list of unclear items / questions:
• Does Takt really increase the satisfaction of the customer or does is only increase the OTR? Does the customer not go to another party if that party could deliver the desired quantity? • Who has to do the red (urgent) order(s)?
• What to do with the operators when no more cards are available and these operators do not have the skills to work on current WIP orders?
• What are we going to do with the priority lists?
• Why is Takt not introduced over all MACHINE COLLECTION’s at once? • Why doesn’t MACHINE COLLECTION-1 have Takt?
• Who is the boss the planner or the supervisor?
• Imagine that there are 60 cards at milling and the turning machines are not having any cards. WIP Sawing and Soldering
0 10 20 30 40 50 60 70 80 5- 30-2008 6-2008 6- 13-2008 6- 20-2008 6- 27-2008 7- 4-2008 7- 11-2008 7- 18-2008 7- 25-2008 8- 1-2008 8-2008 Date Or d e rs
