A Fr a m e w or k for H e a lt h Ca r e Pla n n in g a n d Con t r ol
Erw in W. Hans1*
Mark Van Houdenhoven2 Pet er J.H. Hulshof1,3
1 Universit y of Tw ent e, Enschede, t he Net herlands 2 Haga Ziekenhuis, Den Haag, t he Net herlands 3 Reinier de Graaf Groep, Delft , t he Net herlands
* Corresponding aut hor: e .w .h a n s@u t w e n t e .n l, + 31( 0) 534893523, Universit y of Tw ent e, P.O. box 217, 7500 AE, Enschede, t he Net herlands
Abst r a ct
Rising expendit ures spur healt h care organizat ions t o organize t heir processes m ore efficient ly and effect ively. Unfort unat ely, healt h care planning and cont rol lags far behind m anufact uring planning and cont rol. Successful m anufact ur ing planning and cont rol concept s can not be direct ly copied, because of t he unique nat ure of healt h care delivery. We analy ze exist ing planning and cont rol concept s or fram ew orks for healt h care operat ions m anagem ent , and find t hat t hey do not properly address various im port ant planning and cont rol problem s. We conclude t hat t hey only focus on hospit als, and are t oo narrow , focusing on a single m anager ial area, such as resource capacit y planning, or ignor ing hierarchical levels.
We propose a m odern fram ew ork for healt h care planning and cont rol. Our fram ew ork int egrat es all m anager ial areas involved in healt h care delivery operat ions and all hierarchical levels of cont rol, t o ensure com plet eness and coherence of responsibilit ies for every m anagerial area. The fram ew ork can be used t o st ruct ure t he various planning and cont rol funct ions, and t heir int eract ion. I t is applicable broadly, t o an indiv idual depart m ent , an ent ire healt h care organizat ion, and t o a com plet e supply chain of cure and care providers. The fram ew ork can be used t o ident ify and posit ion var ious t ypes of m anagerial problem s, t o dem arcat e t he scope of organizat ion int ervent ions, and t o facilit at e a dialogue bet w een clinical st aff and m anagers. We illust rat e t he applicat ion of t he fram ew ork w it h exam ples.
Ke y w or ds: organizat ional decision m aking, int egrat ed planning and cont rol,
1 I n t r odu ct ion
Planning and cont rol in healt h care has received an increased am ount of at t ent ion over t he last t en years, bot h in pract ice and in t he lit erat ure. This at t ent ion is due t o an increase in dem and for healt h care and increasing expendit ures [ 28] . As a result , healt h care organizat ions are t rying t o re-organize processes m ore efficient ly and effect ively. I t is t herefore not surprising t hat t he Operat ions Research/ Managem ent Science ( OR/ MS) research com m unit y’s int erest in healt h care applicat ions is st eadily increasing [ 4] . I n fact , t he at t endance of t he conference of t he EURO Work ing Group on Operat ional Research Applied t o Healt h Services ( ORAHS [ 29] ) has increased from around 50 in 2002 t o 150 in 2009 , and involves an increasing num ber of count ries. Wit hin t hese research effort s, planning and cont rol is a key focal area – t he subj ect of m ore t han 35% of t he ORAHS publicat ions [ 5] .
Planning and cont rol has a rich t radit ion in m anufact uring. Graves [ 16] st at es t hat " Manufact uring planning and cont rol address decisions on t he acquisit ion, ut ilizat ion and allocat ion of product ion resources t o sat isfy cust om er requirem ent s in t he m ost efficient and effect ive w ay." Planning and cont rol com prises int egrat ed coordinat ion of resources ( st aff, equipm ent and m at erials) and product flow s, in such a w ay t hat t he organizat ion’s obj ect ives are realized [ 1] .
Healt h care planning and cont rol lags far behind m anufact ur ing planning and cont rol. Com m on reasons st at ed in t he lit er at ure include:
1. Healt h care organizat ions are professional organizat ions w hich oft en lack cooperat ion bet w een, or com m it m ent from , involved part ies ( doct ors, adm inist rat ors, et c.) . These groups have t heir ow n, som et im es conflict ing, obj ect ives, as is nicely illust r at ed by Glouberm an and Mint zberg in t heir “ four faces of healt h care” fram ew ork [ 14,15] .
2. Due t o t he st at e of inform at ion syst em s in healt h care, crucial inform at ion required for planning and cont rol is oft en not available [ 8] . Alt hough Diagnosis Relat ed Gr oups ( DRGs) and elect ronic healt h record syst em s have spurred t he need for financial and clinical inform at ion m anagem ent syst em s, t hese syst em s t end t o be poorly int egrat ed w it h operat ional inform at ion
syst em s. This lack of int egrat ion is im peding t he advance of int egrat ed planning and cont rol in healt h care, bot h organizat ion- w ide and bet w een organizat ions. This w as recognized already in 1995 by Rot h and Van Dierdonck [ 34] , but developm ent s unt il now have been slow [ 21] .
3. Since large healt h care providers such as hospit als generally consist of aut onom ously m anaged depart m ent s, m anagers t end not t o look beyond t he border of t heir depart m ent , and planning and cont rol is fragm ent ed [ 32,34] . 4. The Hippocrat ic Oat h t aken by doct ors forces t hem t o focus on t he pat ient at
hand, w hereas planning and cont rol addresses t he ent ire pat ient populat ion, bot h w it hin and beyond t he scope of an indiv idual doct or [ 26,27] .
5. While healt h care m anagers are generally dedicat ed t o prov ide t he best possible serv ice, t hey lack t he know ledge and t raining t o m ake t he best use of t he available resources [ 8] .
6. As healt h care m anagers oft en feel t hat invest ing in bet t er adm inist rat ion divert s funds from direct pat ient care [ 8] , m anagerial funct ions are oft en ill-defined, over looked, poorly addressed, or funct ionally dispersed.
I n t his paper w e propose and dem onst rat e a hierarchical fram ew ork for healt h care planning and cont rol t o help overcom e t he aforem ent ioned problem s. This fram ew ork serves as a t ool t o st ruct ure and break dow n all funct ions of healt h care planning and cont rol. I n addit ion, it can be used t o ident ify planning and cont rol problem s and t o dem arcat e t he scope of organizat ion int ervent ions. I t is applicable broadly, fr om an indiv idual hospit al depart m ent t o an ent ire hospit al, or t o a com plet e supply chain of care providers. The fram ew ork facilit at es a dialogue bet w een clinical st aff and m anagers t o design t he planning and cont rol m echanism s. These m echanism s are necessary t o t ranslat e t he organizat ion’s obj ect ives int o effect ive and efficient healt h care delivery processes [ 13] . I t covers all m anager ial areas involved in healt h care delivery operat ions and all levels of cont rol, t o ensure com plet eness and coherence of responsibilit ies for every m anagerial area.
We w ill ar gue in Sect ion 2 t hat w hile fram ew orks for planning and cont rol do exist in t he lit erat ure, t hey m ost ly focus on one m anagerial area – in part icular resource capacit y planning or m at er ials planning – and m ost ly only focus on hospit als. The cont ribut ion of our fram ew ork is t hat it encom passes all
m anagerial areas, including t hose t ypically overlooked by ot hers. I n part icular , m edical planning ( i.e. decision m ak ing by clinicians) and financial planning should not be over looked w hen healt h care delivery processes are t o be redesigned or opt im ized. Anot her cont ribut ion of t he fram ew ork is it s hierarchical decom posit ion of m anager ial levels, w hich is an ext ension of t he classical st rat egic- t act ical- operat ional breakdow n [ 1] , oft en used in m anufact ur ing. Finally , w hile m ost fram ew orks focus on hospit als, our fram ew ork can be applied t o any t ype of healt h care delivery or ganizat ion.
This paper is organized as follow s. Sect ion 2 out lines t he lit erat ure on fram ew orks for planning and cont rol. Sect ion 3 present s t he generic fram ew ork for healt h care planning and cont rol. Sect ion 4 descr ibes how t o ident ify m anagerial problem s w it h t he fram ew or k, and dem onst rat es it s applicat ion. Sect ion 5 present s concluding rem arks.
2 Lit e r a t u r e on fr a m e w or k s for pla n n in g a n d con t r ol
I n t his sect ion w e give an overview of t he st at e- of- t he art in t he lit erat ure of bot h m anufact uring planning and cont rol and healt h care planning and cont rol. We also discuss t he st rengt hs and w eaknesses of t he exist ing fram ew orks.
Alm ost all w ell- know n fram ew orks for m anufact uring planning and cont rol ( MPC) organize planning and cont rol funct ions hierarchically . I t reflect s t he nat ural process of increasing disaggregat ion in decision m ak ing as t im e progresses, and m ore inform at ion becom es available [ 41] . I t also reflect s t he hierarchical ( depart m ent ) st ruct ure of m ost organizat ions [ 2] . Many MPC fram ew orks use t he hierarchical decom posit ion int o a st rat egic, t act ical, and operat ional level, as first done by Ant hony in 1965 [ 1] .
The classical MPC fram ew orks have a specific or ient at ion on eit her product ion planning ( e.g. hierarchical product ion planning [ 19] ) , or t echnological ( or process) planning ( e.g. com put er aided process planning [ 25] ) , or m at erial planning ( e.g. Mat erial Requirem ent s Planning ( MRP) [ 30] ) . As argued by Zij m in [ 41] , t his m yopic or ient at ion t o one m anagerial area is t he m ain cause t hat t hese MPC fram ew orks are inadequat e in pract ice. Modern MPC fram ew orks int egrat e t hese orient at ions: t he fram ew orks of [ 41] and [ 18] are designed for
int egrat ed MPC in highly com plex organizat ions, such as engineer- t o- order m anufact urers.
Various researchers have proposed fram ew orks for ( hierarchical) planning and cont rol in healt h care. I n t he rem ainder of t his sect ion, w e give an overv iew of exist ing fram ew orks for healt h care planning and cont rol.
First int roduced in [ 33] , and lat er expanded on by Rot h and Van Dierdonck in [ 34] , t w o papers propose a hierarchical fr am ew ork t hat is based on applicat ion of t he Manufact uring Resource Planning ( MRP- I I ) concept . This fram ew ork considers bot h resource capacit y planning and m at er ial planning, and focuses specifically on hospit als. I t relies on DRGs w hich serve as t he “ bill of m at er ials” in MRP- I I t o derive t he resource and m at erial requirem ent s of pat ient groups. Rot h and Van Dierdonck [ 34] propose t o use DRGs t o facilit at e int egrat ed hospit al- w ide planning and cont rol. Vissers and Beech [ 37] crit icize t his fram ew ork, and argue t hat alt hough DRGs are an excellent t ool t o m arket and finance hospit als, t hey are not a good basis for logist ical cont rol and m anaging day- t o- day operat ions.
Vissers et al. [ 38] and De Vries et al. [ 12] propose a fram ew ork for product ion cont rol in hospit als. The approach assum es t he com m on sit uat ion t hat a hospit al is organized in relat ively independent business unit s. I t is lim it ed t o resource capacit y planning, for w hich it dist inguishes five hierarchical levels: st rat egic planning, pat ient volum es planning and cont rol, resources planning and cont rol, pat ient group planning, and pat ient planning and cont rol. These levels address “ offline” ( in advance) decision m ak ing. “ Online” ( react ive) operat ional cont rol funct ions such as react ive planning ( for exam ple, add- on scheduling upon arr ival of an em ergency case) and m onit or ing are not considered in t heir fram ew ork.
But ler et al. [ 6] em phasize t hat due t o t he differ ing com plex it y and inform at ion requirem ent s of t he var ious decisions, organizat ional planning processes are com m only hierarchical in nat ure. The first st ep, on a st rat egic level, involves st rat egy form at ion, process layout design, and long- t erm capacit y dim ensioning. Subsequent st eps relat e increasingly t o operat ional concerns, wit h a decreasing planning horizon and increasing inform at ion availabilit y. The hierarchical levels
of cont rol are linked: for exam ple long- t erm capacit y dim ensioning decisions shape t he capacit y rest rict ions for subsequent operat ional decision m ak ing. The perform ance, w hich is m easured at an oper at ional level, is t he result of how w ell t he var ious hierarchical planning act iv it ies are int egrat ed. I n anot her paper, But ler et al. [ 7] indicat e t hat t he lit er at ure neglect s cooperat ion bet w een different m anagerial areas at t he st rat egic level of hospit al planning and cont rol. They argue t hat t o at t ain except ional operat ional perform ance, it is im port ant t hat t he hospit al’s st rat egy consist ent ly and coherent ly int egrat es operat ions issues from areas like Finance, Market ing, Operat ions, and Hum an Resources.
Blake and Cart er [ 3] focus on an operat ing t heat re set t ing, for w hich t hey propose a hierarchical fram ew ork for resource planning and appoint m ent scheduling w it h t hree hierarchical levels: st rat egic, adm inist rat ive ( t act ical) , and operat ional planning.
We conclude t hat all exist ing fram ew orks for healt h care planning and cont rol focus on hospit als, and are hierarchical in nat ure. How ever, like m any MPC fram ew orks t hey also focus on j ust one m anagerial area – m ost ly resource capacit y planning. I nt egrat ion of m anager ial areas is neglect ed, as w ell as t he react ive decision funct ions, w hich are im port ant given t he inherent ly st ochast ic nat ure of healt h car e processes. Modern MPC fram ew orks [ 18,41] , how ever, address m ult iple m anagerial areas as w ell as t he t hree w ell- know n hierarchical levels of cont rol. These fram ew orks w ere designed for engineer- t o- order or m anufact ure- t o- order environm ent s, w here uniquely specified product s are produced on dem and. I n t his aspect , t hese environm ent s resem ble healt h care delivery . Therefore, t hese MPC fram ew orks offer a sound basis for our fram ew ork for healt h care planning and cont rol. How ever, for applicat ion in healt h care, t hey require significant m odificat ion. I n t he follow ing sect ion, w e int roduce our generic fram ew ork.
3 A ge n e r ic fr a m e w or k for h e a lt h ca r e pla n n in g a n d con t r ol
We propose a four- by- four generic fram ew ork for healt h car e planning and cont rol w hich spans four hierarchical levels of cont rol, and four m anagerial areas. We first discuss t he m anagerial ar eas ( 3.1) , and t hen t he hierarchical decom posit ion ( 3.2) . We t hen com bine t hese t w o dim ensions t o form t he
fram ew ork for healt h care planning and cont rol ( 3.3) . Finally , w e discuss t he cont ext of t he fram ew ork and how it affect s t he cont ent ( 3.4) .
3 .1 M a n a ge r ia l a r e a s
As out lined in Sect ion 2, m ost ex ist ing fram ew orks in t he lit erat ure focus on one m anagerial area. We propose t o include t he follow ing m anagerial areas for healt h care planning and cont rol: m edical planning, resource capacit y planning, m at erials planning, and financial planning. We describe t hese areas in m ore det ail below.
Medical planning
The role of engineers/ process planners in m anufact ur ing is perform ed by clinicians in healt h care. We refer t o healt h care’s version of “ t echnological planning” as m edical planning. Medical planning com pr ises decision m ak ing by clinicians regarding for exam ple m edical prot ocols, t reat m ent s, diagnoses, and t riage. I t also com prises developm ent of new m edical t reat m ent s by clinicians. The m ore com plex and unpredict able t he healt h care processes, t he m ore aut onom y is required for clinicians. For exam ple, act iv it ies in acut e care are necessarily planned by clinicians, w hereas in elect ive care ( e.g. am bulat ory surgery) , st andardized and predict able act iv it ies can be planned cent rally by m anagem ent .
Resource capacit y planning
Resource capacit y planning addresses t he dim ensioning, planning, scheduling, m onit or ing, and cont rol of renew able resources. These include equipm ent and facilit ies ( e.g. MRI s, physical t herapy equipm ent , bed linen, st erile inst rum ent s, operat ing t heat res, rehabilit at ion room s) , as w ell as st aff.
Mat erials planning
Mat erials planning addresses t he acquisit ion, st orage, dist r ibut ion and ret rieval of all consum able resources/ m at erials, such as sut ure m at erials, prost heses, blood, bandages, food, et c. Mat erials planning t ypically encom passes funct ions like w arehouse design, invent ory m anagem ent and purchasing.
Financial planning
Financial planning addresses how an organizat ion should m anage it s cost s and revenues t o achieve it s obj ect ives under current and fut ure organizat ional and econom ic circum st ances. Since healt h care spending has been increasing st eadily [ 28] , m ar ket m echanism s are being int roduced in m any count ries as an incent ive t o encourage cost - efficient healt h care delivery ( see e.g. [ 40] ) . An exam ple is t he int roduct ion of Diagnosis- Relat ed Groups ( DRGs) , w hich enables t he com parison of care product s and t heir prices. As healt h care syst em s differ per count ry, so does financial planning in healt h care organizat ions. As financial planning heavily influences t he w ay t he processes are organized and m anaged, w e include t his m anagerial area in our fr am ew ork. For exam ple, Wacht el and Dext er [ 39] argue t hat in t he US, t he t act ical allocat ion of t em porary expansions in operat ing t heat re capacit y should be based on t he cont ribut ion m argin of t he involved surgical ( sub) specialt ies. This crit er ion is not likely t o be used in count ries w it h a non- com pet it ive healt h care syst em , such as t he UK or t he Net herlands. Financial planning in healt h care concerns funct ions such as invest m ent planning, cont ract ing ( w it h e.g. healt h care insurers) , budget and cost allocat ion, account ing, cost pr ice calculat ion, and billing.
We have select ed t hese four m anagerial ar eas, as w e consider t hese as relevant in all our research proj ect s t hat revolve around opt im izat ion of healt h care operat ions [ 9] .
3 .2 H ie r a r ch ica l de com posit ion
As argued in Sect ion 2, decision m ak ing disaggregat es as t im e progresses and inform at ion gradually becom es available. We build upon t he “ classical” hierarchical decom posit ion oft en used in m anufact ur ing planning and cont rol, w hich discerns st rat egic, t act ical, and operat ional levels of cont rol [ 1] . We ext end t his decom posit ion by discerning bet w een offline and online on t he operat ional level. This dist inct ion reflect s t he difference bet w een “ in advance” decision m ak ing and “ react ive” decision m aking. We explain t he result ing four hierarchical levels below, w here t he t act ical level is explained last . The t act ical level is oft en considered less t angible t han t he st rat egic and operat ional levels, as w e w ill fur t her ex plain in Sect ion 4. Therefore, w e explain t he m ore t angible levels first , before addressing t he t act ical level.
Not e t hat w e do not explicit ly give t he decision hor izon lengt h for any of t he hierarchical planning levels, since t hese depend on t he specific charact erist ics of t he applicat ion. An em ergency depart m ent for exam ple inherent ly has short er planning hor izons t han a long- st ay w ard in a nursing hom e.
St rat egic level
St rat egic planning addresses st ruct ural decision m ak ing. These decisions are t he bricks and m ort ar of an organizat ion [ 24] . I t involves defining t he organizat ion’s m ission ( i.e. “ st rat egy” or “ direct ion” ) , and t he decision m aking t o t ranslat e t his m ission int o t he design, dim ensioning, and developm ent of t he healt h care delivery process. I nherent ly, st rat egic planning has a long planning hor izon and is based on highly aggregat ed inform at ion and forecast s. Exam ples of st rat egic planning are resource capacit y expansions ( e.g. acquisit ion of MRI m achines) , developing and/ or im plem ent ing new m edical prot ocols, form ing a purchasing consort ium , a m erger of nursing hom es, and cont ract ing w it h healt h insurers.
Offline operat ional lev el
Operat ional planning ( bot h “ offline” and “ online” ) involves t he short - t erm decision m aking relat ed t o t he execut ion of t he healt h care delivery process. There is low flex ibilit y on t his planning level, since m any decisions on higher levels have dem arcat ed t he scope for t he operat ional level decision m ak ing. The adj ect ive “ offline” reflect s t hat t his planning level concerns t he in advance planning of operat ions. I t com prises t he det ailed coordinat ion of t he act ivit ies regarding current ( elect ive) dem and. Exam ples of offline operat ional planning are: t reat m ent select ion, appoint m ent scheduling, nurse rost ering, invent ory replenishm ent ordering, and billing.
Online operat ional level
The st ochast ic nat ure of healt h care processes dem ands for react ive decision m ak ing. “ Online” operat ional planning involves cont rol m echanism s t hat deal w it h m onit or ing t he process and react ing t o unforeseen or unant icipat ed event s. Exam ples of online planning funct ions are: t riaging, add- on scheduling of em ergencies, replenishing deplet ed invent ories, rush or dering surgery inst rum ent st er ilizat ion, handling billing com plicat ions.
Tact ical level
I n bet w een t he st rat egic level, w hich set s t he st age ( regarding e.g. locat ion and size) , and t he operat ional level, w hich addr esses t he execut ion of t he processes, lies t he t act ical planning level. We explain t act ical planning in relat ion t o st rat egic and operat ional planning.
While st rat egic planning addresses st ruct ural decision m ak ing, t act ical planning addresses t he organizat ion of t he operat ions / execut ion of t he healt h care delivery process ( i.e. t he “ w hat , w here, how , w hen and w ho” ) . I n t his w ay, it is sim ilar t o operat ional planning, how ever, decisions are m ade on a longer planning hor izon. The lengt h of t his int erm ediat e planning horizon lies som ew here bet w een t he st rat egic planning horizon and operat ional planning horizon. Follow ing t he concept of hierarchical planning, int er m ediat e, t act ical planning has m ore flexibilit y t han operat ional planning, is less det ailed, and has less dem and cert aint y. Conversely , t he opposit e is t rue w hen com pared t o st rat egic planning.
For exam ple, w hile capacit y is fixed in operat ional planning, t em porary capacit y expansions like overt im e or hir ing st aff ar e possible in t act ical planning. Also, w hile dem and is lar gely know n in operat ional planning, it has t o be ( part ly) forecast ed for t act ical planning, based on ( seasonal) dem and, w ait ing list inform at ion, and t he “ dow nst ream ” dem and in care pat hw ays of pat ient s current ly under t reat m ent . Due t o t his dem and uncert aint y , t act ical planning is less det ailed t han operat ional planning ( consider for exam ple block planning vs. appoint m ent scheduling) . Exam ples of t act ical funct ions are adm ission planning, block planning, t reat m ent select ion, supplier select ion and budget allocat ion.
3 .3 Fr a m e w or k for h e a lt h ca r e pla n n in g a n d con t r ol
I nt egrat ing t he four m anagerial areas and t he four hierarchical levels of cont rol shapes a four- by- four posit ioning fram ew ork for healt h car e planning and cont rol. While t he dim ensions of t he fram ew ork are generic, t he cont ent depends on t he applicat ion at hand. The fram ew or k can be applied any w here from t he depart m ent level ( for exam ple t o an operat ing t heat re depart m ent ) t o organizat ion- w ide, or t o a com plet e supply chain of care prov iders. Depending on t he cont ext , t he cont ent of t he fram ew ork m ay be very different . Figure 1
show s t he cont ent of t he fram ew ork w hen applied t o a gener al hospit al as a w hole. The insert ed planning and cont r ol funct ions are exam ples, and not exclusive. St r a t e gic Of flin e ope r a t ion a l Ta ct ica l Case m ix planning, capacit y dim ensioning,
wor kfor ce planning Block planning, st affing, adm ission
planning Appoint m ent scheduling, wor kfor ce
scheduling
Supply chain and war ehouse design
Supplier select ion, t ender ing
Mat er ials pur chasing, det er m ining or der
sizes Re sou r ce ca pa cit y pla n n in g M a t e r ia ls pla n n in g M e dica l pla n n in g
Tr eat m ent select ion, pr ot ocol select ion
Diagnosis and planning of an individual t r eat m ent
Resear ch, developm ent of m edical pr ot ocols
Fin a n cia l pla n n in g I nvest m ent plans,
cont r act ing wit h insur ance com panies
Budget and cost allocat ion
DRG billing, cash flow analy sis
Monit or ing, em er gency coor dinat ion
Rush or der ing, invent or y r eplenishing Tr iage, diagnosing
em er gencies and com plicat ions On lin e ope r a t ion a l m anagerial areas h ie ra rc h ic a l d e c o m p o s it io n
Billing com plicat ions and changes
Fig. 1 Exam ple applicat ion of t he fram ew ork for healt h car e planning and cont rol t o a general hospit al
3 .4 Con t e x t of t h e fr a m e w or k
As argued in t he pr evious sect ion, t he cont ent of t he fram ew ork should be accom m odat ed t o t he cont ext of t he applicat ion. Regarding t he cont ext w e discern t he int ernal and ext ernal env ironm ent charact erist ics.
The int ernal environm ent charact erist ics are scoped by t he boundaries of t he organizat ion. This involves all charact er ist ics t hat affect planning and cont rol, regarding for exam ple pat ient dem and ( e.g. var iabilit y , com plex it y , arr ival int ensit y , m edical urgency, recurrence) , organizat ional cult ure and st ruct ure.
The w ay healt h care organizat ions are organized is perhaps m ost influenced by it s ext ernal env ironm ent . For exam ple a “ STEEPLED” analysis ( an ext ension of “ PESTEL” , see e.g. [ 20] ) can be done t o ident ify ext ernal fact ors t hat influence healt h care planning and cont rol, now or in t he fut ure. “ STEEPLED” is an abbreviat ion for t he follow ing ext ernal env ironm ent fact ors:
• Social fact ors ( e.g. educat ion, social m obilit y, religious at t it udes) • Technology ( e.g. m edical innovat ion, t ransport infrast ruct ure)
• Econom ic fact ors ( e.g. change in healt h finance syst em ) • Environm ent al fact ors ( e.g. ecological, recy cling)
• Polit ical fact ors ( e.g. change of governm ent policy , pr ivat izat ion) • Legislat ion / Legal ( e.g. business regulat ions, qualit y regulat ions) • Et hical fact ors ( e.g. business et hics, confident ialit y, safet y)
• Dem ographics ( e.g. gray ing populat ion, life expect ancy, obesit y)
These fact ors largely explain t he differences am ongst count ries in t he m anagem ent approach of healt h care organizat ions. Figure 2 illust rat es how t he fram ew ork can be observed in light of t he organizat ion’s ext ernal env ironm ent .
Social
Technology
Econom ic Dem ographics
Env ironm ent al
Polit ical Legislat ion Et hical St r a t e gic Ta ct ica l Re sou r ce ca pa cit y pla n n in g M a t e r ia ls pla n n in g M e dica l pla n n in g Fin a n cia l pla n n in g Of flin e ope r a t ion a l On lin e ope r a t ion a l Ex t e r n a l e n vir on m e n t I n t e r n a l e n v ir on m e n t
Fig. 2 The fram ew ork and t he organizat ion’s ext ernal environm ent
4 Applica t ion of t h e fr a m e w or k
The prim ary obj ect ive of t he fram ew ork is t o st ruct ure t he various planning and cont rol funct ions. I n t his sect ion, w e give exam ples of how t he fr am ew ork can be applied. Sect ion 4.1 discusses how t he fram ew ork can be used t o ident ify m anagerial deficiencies. Sect ion 4.2 gives an exam ple of an applicat ion of t he fram ew ork t o an int egrat ed m odel for pr im ary care out side office hours.
4 .1 I de n t ifica t ion of m a n a ge r ia l de ficie n cie s
Once t he cont ent of t he fram ew ork has been est ablished for a given applicat ion, furt her analysis of t his cont ent m ay ident ify m anager ial pr oblem s. I n t he rem ainder of t his sect ion, w e discuss exam ples of four k inds of t ypical problem s: 1. Deficient or lack ing planning funct ions
2. I nappropriat e planning approaches
3. Lack of coherence bet w een planning funct ions 4. Planning funct ions t hat have conflict ing obj ect ives
Sub 1. Deficient or lacking planning funct ions
Overlooked or poorly addressed m anagerial funct ions can be encount ered on all levels of cont rol [ 8] , but are oft en found on t he t act ical level of cont rol [ 34] . I n fact , t o m any, t act ical planning is less t angible t han operat ional planning and even st rat egic planning. I nundat ed w it h operat ional problem s, m anagers are inclined t o solve problem s at hand ( i.e., on t he operat ional level) . We refer t o t his phenom enon as t he “ real- t im e hype” of m anagers. A claim for “ m ore capacit y” is t he universal panacea for m any healt h care m anagers. I t is, how ever, oft en overlooked t hat inst ead of such drast ic st rat egic m easures, t act ically allocat ing and organizing t he available resources m ay be m ore effect ive and cheaper. Consider for exam ple a “ m ast er schedule” or “ block plan” , w hich is t he t act ical allocat ion of blocks of resource t im e ( e.g. operat ing t heat res, or CT-scanners) t o specialt ies and/ or pat ient cat egories dur ing a w eek. Such a block plan should be periodically revised t o react on variat ions in supply and dem and. How ever, in pract ice, it is m ore oft en a result of “ hist or ical developm ent ” t han of analyt ical considerat ions [ 36] .
An exam ple of a deficient planning funct ion is w hen aut onom y is given t o or assum ed by t he w rong st aff m em ber. We illust rat e t his w it h t w o exam ples. ( 1) Spurred by t he Oat h of Hippocrat es, clinicians m ay t ry t o ‘cheat ’ t he syst em t o advance a pat ient . Alt hough t his m ay appear subopt im al from a cent ral m anagem ent point of v iew , it m ay be necessary from a m edical point of v iew . The crux is t o put t he aut onom y w here it is act ually needed. This depends on t he applicat ion at hand. As argued earlier, t he m ore com plex and unpredict able t he healt h care processes, t he m ore aut onom y is required for clinicians. St andardized and pr edict able act iv it ies can how ever be planned cent rally by
m anagem ent , w hich is advant ageous from an econom ies of scale view point . ( 2) I nt ravenous drip pum ps are com m only a resource shared by w ards. Wards t ypically hoard t hem , t o ensure im m ediat e availabilit y [ 11] . This leads t o excessive invent ory ( cost s) , w hich m ay be significant ly reduced by cent ralizing m anagem ent and st orage of t his equipm ent .
Sub 2. I nappropriat e planning approaches
There are m any logist ical paradigm s, such as Just - I n- Tim e ( JI T) , Kanban, Lean, Tot al Qualit y Managem ent ( TQM) , and Six Sigm a, all of w hich have report ed success st ories. As t hese paradigm s are m ost ly developed for indust r y, t hey generally cannot be sim ply copied t o healt h care w it hout im punit y . “ The t endency t o uncrit ically em brace a solut ion concept , developed for a rat her specific m anufact ur ing environm ent , as t he panacea for a v ariet y of ot her problem s in t ot ally different environm ent s has led t o m any disappoint m ent s” [ 41] . The st ruct ure provided by t he fram ew ork helps t o ident ify w het her a planning approach is suit able for a planning funct ion in a part icular organizat ional env ironm ent . Planning appr oaches are only suit able if t hey fit t he int ernal and ext ernal charact erist ics of t he involved applicat ion. They have t o be adapt ed t o / designed for t he charact erist ics t hat are unique for healt h care delivery , such as: ( 1) pat ient part icipat ion in t he serv ice process; ( 2) sim ult aneit y of product ion and consum pt ion; ( 3) per ishable capacit y; ( 4) int angibilit y of healt h care out put s; and ( 5) het erogeneit y [ 31] .
Sub 3. Lack of coherence bet w een planning funct ions
The effect iveness and efficiency of healt h care delivery is not only det erm ined by how t he var ious planning funct ions are addressed; t his is also det erm ined by how t hey int eract . As healt h care providers such as hospit als are t ypically form ed as a clust er of aut onom ous depart m ent s, planning is also oft en funct ionally dispersed. The fram ew ork st ruct ures planning funct ions, and provides insight in t heir hor izont al ( cross- m anagem ent ) and vert ical ( hierarchical) int eract ions. Horizont al int er act ion bet w een m anagerial areas in t he fram ew ork provides t hat required m edical inform at ion and prot ocols, and all involved resources and m at erials, are brought t oget her t o enable bot h effect ive and efficient healt h care delivery . Dow nw ard vert ical int eract ion concerns concret izing higher level obj ect ives and decisions on a short er planning hor izon.
For exam ple, capacit y dim ensioning decisions on a st rat egic level ( e.g. num ber of CT scanners) im pose hard rest rict ions on t act ical and operat ional planning and scheduling. Upw ar d v ert ical int eract ion concerns feedback about t he realizat ion of higher level obj ect ives. For exam ple t he capacit y of MRI m achines is det erm ined on t he st rat egic level t o at t ain a cert ain serv ice level ( e.g. access t im e) . Feedback from t he t act ical and operat ional level is t hen needed t o observe w het her t his obj ect ive is act ually at t ained, and t o adv ise t o w hat ext ent t he capacit y is sufficient .
Sub 4. Planning funct ions t hat have conflict ing obj ect ives
As argued, t he fram ew ork st ruct ures planning funct ions and t heir horizont al and vert ical int eract ions. The fram ew ork can t hus ident ify conflict ing obj ect ives bet w een planning funct ions. For exam ple, m inim al- invasive surgery generally result s in significant reduced lengt h of st ay in w ards and im proved qualit y of care, but result s in higher cost s and increased capacit y consum pt ion for t he operat ing t heat re depart m ent . These depart m ent s are oft en m anaged aut onom ously and independent ly, w hich leads t o sub- opt im al decision m ak ing from bot h t he pat ient ’s and t he hospit al’s point of v iew .
Conflict ing obj ect ives also occur bet w een t w o care providers in an int er-organizat ional care chain. For exam ple a nursing hom e’s st rive t o m ax im ize occupat ion w ill lead t o bed blocking in hospit als. Aligning planning funct ions bet w een healt h care organizat ions m ay ident ify and solve such problem s.
4 .2 Applica t ion of t h e fr a m e w or k t o pr im a r y ca r e ou t side office h ou r s I n t his sect ion w e give an exam ple applicat ion of t he fram ew ork. First w e int roduce t he cont ext : t he concept of an int egrat ed organizat ion t hat prov ides prim ary care out side office hours. We t hen dem onst rat e how t he fram ew ork can facilit at e t he discussion regarding t he design of such an organizat ion.
I n t r odu ct ion
The organizat ion of prim ary care out side office hours, w hich inv olves t elephone t riage, urgent consult at ions and house calls, has received increasing at t ent ion in m any count ries [ 17] . I n part s of Europe, general pract it ioners ( GPs) are required by law t o prov ide t his t ype of care, and in som e count ries, GPs cooperat e in
prim ary care cooperat ives ( PCCs) t o j oint ly prov ide pr im ary care out side office hours. Wit hin a PCC, t he GPs can alt ernat e w ho is responsible out side office hours. As a result , t hese GPs do not alw ays have t o be available out side office hours. Alt ernat ive t o t he PCC, pat ient s r equir ing pr im ary car e out side office hours can visit t he em ergency depart m ent ( ED) of a hospit al. Alt hough EDs are int ended for com plex urgent care, t hey deal w it h a relat ively large group of pat ient s t hat could have been served by a GP. For exam ple a st udy at King’s College Hospit al in t he Unit ed Kingdom report s t hat 41% of pat ient s visit ing t he ED could have been t reat ed by a GP [ 10] . Ev ident ly, it is m or e cost ly t o serve t hese so- called ‘self referrals’ at t he ED. Therefore, m et hods are proposed t o ensure t hese pat ient s are served by GPs and do not v isit an ED. One of t he proposed m et hods is an int egrat ed m odel, w here t he PCC is locat ed in close proxim it y t o t he ED, w it h a j oint t r iage syst em . I nt egrat ed m odels are effect ive in t he UK [ 22] , and are also favored by t he Net herlands as t he appropr iat e syst em for em ergency care [ 35] . A survey [ 35] show ed t hat t he int egrat ed m odel significant ly decreases t he num ber of self referrals in t he ED, since t hese pat ient s can be referred t o t he PCC. The int egrat ion is t hus cost effect ive from a societ al point of v iew [ 10,35] . I t is, how ever, under debat e w het her t he int egrat ion is cost effect ive for t he EDs and PCCs [ 35] . For EDs, t he int egrat ion decreases t he num ber of pat ient v isit s, possibly around 50% [ 17] . This reduces t urnover, and all k inds of econom ies- of- scale advant ages. I n t he Net herlands, t he hourly rat e for prim ary care out side office hours for GPs ( set by governm ent and paid by healt h insurers) is considered low and not profit able. Hence, GPs do not w elcom e t he increased w orkload.
Applica t ion of t h e fr a m e w or k
To successfully im plem ent an int egrat ed ED/ PCC, t he involv ed part ies m ust address t he aforem ent ioned problem s, and discuss how t o m anage t he new organizat ion’s planning and cont rol. To facilit at e t his discussion in a st ruct ured w ay, t he fram ew ork can be inst rum ent al. We m ent ion som e of t he key issues per m anagerial area:
• Medical planning: How does t he case of j oint t r iage affect t he role and responsibilit ies of t he GPs, w ho before w ere considered t he ‘gat ekeepers’ of healt h care deliver y?
• Resource capacit y planning: What are t he “ 24/ 7” resource capacit y requirem ent s? I s collaborat ion of ED and PCC st aff possible despit e t he fact t hat t hey w ork for t w o independent cost cent ers – if so, t o w hat ext ent should t hey collaborat e?
• Mat erials planning: Should t he ED and PCC j oint ly purchase m at erials? Where should invent ories be kept , and w ho has ow nership?
• Financial planning: I s an int egrat ion of ED and PCC cost effect ive for hospit als, GPs, insurance com panies, societ y? I s it profit able for t he ED t o em ploy general pract it ioners for self referr als inst ead of int egrat ing w it h a PCC? Should hospit als, insurance com panies, or t he governm ent com pensat e GPs for t he increased w orkload? Should t he ED and PCC be int egrat ed int o one cost cent er?
Based on t he out com es of t he discussion around t he aforem ent ioned issues, t he fram ew ork can be used furt her t o design appropriat e planning and cont rol on all hierarchical levels and in all m anager ial ar eas.
5 Con clu sion s
The increasing cost s of healt h care and t he int roduct ion of ( m anaged) com pet it ive healt h care have spurred t he need for im prov ed healt h care m anagem ent . I n t his paper w e propose a reference fram ew ork for healt h care planning and cont rol, w hich hierarchically st ruct ures planning and cont rol funct ions in m ult iple m anager ial areas. I t offers a com m on language for all involved decision m akers: clinical st aff, m anagers, and expert s on planning and cont rol. This allow s coherent ly form ulat ing and realizing obj ect ives on all levels and in all m anager ial areas [ 13] . The fram ew ork is w idely applicable, t o any t ype of healt h care prov ider, or t o specific depart m ent s w it hin a healt h care organizat ion. The cont ent s of t he fram ew ork depend on t he applicat ion at hand, for exam ple an organizat ional int ervent ion, a decision m ak ing process or a healt h care delivery process.
The fram ew ork facilit at es a st ruct ural analysis of t he planning and cont rol funct ions and t heir int eract ion. Moreover, it helps t o ident ify m anager ial problem s, regarding for exam ple planning funct ions t hat are deficient or inappropr iat e, t hat lack coherence, or have conflict ing obj ect ives. When
m anagerial deficiencies have been ident ified, t he fram ew ork can be used t o dem arcat e t he scope of organizat ion int ervent ions. I n general, focusing on problem s on low er hierarchical levels reduces uncert aint y, as inherent ly t he planning hor izon is short er and m ore infor m at ion is available. How ever, flex ibilit y ( e.g. regarding resource expansion) is also low er. Focusing on problem s on higher hierarchical levels increases t he pot ent ial im pact ( e.g. cost savings, w ait ing t im e reduct ion, qualit y of care) , how ever required invest m ent s are usually also higher, and effect s of int erv ent ions are felt on a longer t erm . Regardless of t he focal point of organizat ion int ervent ions, t he fram ew ork em phasizes t he im plicat ions from and for adj acent m anagerial funct ions. I t can t hus be prevent ed t hat st ake holding decision m akers are not involved, and t hat int ervent ions like “ m ore capacit y” ( t he univ ersal panacea) are not m ade w it hout considering t he possible effect s for all underly ing and relat ed planning funct ions. As a result , int ervent ions w ill have a higher chance of success.
As argued in Sect ion 1, t he lit erat ure regarding t he applicat ion of OR/ MS in healt h care is expanding rapidly. This fram ew ork can also be inst rum ent al in t he design of t axonom ies for, for exam ple, lit erat ure on out pat ient depart m ent ( appoint m ent ) planning, operat ing t heat re planning and scheduling, and invent ory m anagem ent of m edical supplies. Scient ific papers can be posit ioned in t he fram ew ork t o illust rat e t he m anagerial area( s) t hey focus on, and t he hierarchical level of decision m ak ing in t he considered problem ( s) . Sim ilar ly, also algor it hm ic developm ent s can be classified and posit ioned in t he fram ew ork.
The fram ew ork can easily be ext ended t o include ot her m anagerial areas or hierarchical levels. I n part icular inform at ion m anagem ent is a m anagerial area t hat should go hand in hand w it h developm ent of innovat ive organizat ion- w ide planning approaches. " Business- I T Alignm ent " addresses how com panies can apply inform at ion t echnology t o form ulat e and achieve t heir goals on t he var ious hierarchical levels [ 23] . Anot her relevant m anagerial area t hat can be included is qualit y and safet y m anagem ent , w hich is involved in alm ost all care delivery processes, and can be decom posed hierar chically . The fram ew ork can also be expanded in t he hierarchical decom posit ion. There m ay be different funct ions on a single hierarchical level w it hin a m anagerial area, w hich by t hem selves have a nat ural hierarchy . For exam ple decisions regarding t he const ruct ion of a new
building are of a higher level t han decisions regarding t he expansion of a w ard, w hile bot h are st rat egic decisions.
Ack n ow le dge m e n t s
This research is support ed by t he Dut ch Technology Foundat ion STW, applied science div ision of NWO and t he Technology Program of t he Minist ry of Econom ic Affairs.
Re fe r e n ce s
[ 1] Ant hony RN ( 1965) Planning and cont r ol syst em s: a fram ew ork for analysis. Harvard Business School Div ision of Research, Bost on
[ 2] Bert rand JWM, Wort m ann JC, Wij ngaard J ( 1990) Product ion cont rol: a st ruct ural and design orient ed approach. Elsev ier Science I nc. New York, NY
[ 3] Blake JT, Car t er MW ( 1997) Surgical process scheduling: a st ruct ured review . J Soc Healt h Syst 5: 17- 30
[ 4] Brailsford SC, Harper PR, Pat el B, Pit t M ( 2009) An analysis of t he academ ic lit erat ure on sim ulat ion and m odeling in healt h care. J Sim ulat ion 3: 130- 140
[ 5] Brailsford SC and Vissers, JMH ( 2010) OR in healt hcare: a European perspect ive. Eur J Oper Res ( t o appear)
[ 6] But ler TW, Karw an KR, Sw eigart JR ( 1992) Mult i- level st rat egic evaluat ion of hospit al plans and decisions. J Oper Res Soc 43( 7) : 665- 675
[ 7] But ler TW, Keong Leong G, Everet t LN ( 1996) The operat ions m anagem ent role in hospit al st rat egic planning. J Oper Manag 14: 137- 156
[ 8] Cart er M ( 2002) Diagnosis: m ism anagem ent of resources. OR/ MS t oday 29( 2) : 26- 32
[ 9] Cent er for Healt hcare Operat ions I m provem ent and Research ( CHOI R) at t he Universit y of Tw ent e ( 2010) ht t p: / / ww w .ut w ent e.nl/ choir/ . Accessed 25 August 2010
[ 10] Dale J, Lang H, Robert s JA, Green J, Glucksm ann E ( 1996) Cost effect iveness of t reat ing pr im ary care pat ient s in accident and em ergency: a com parison bet w een general pract it ioners, senior house officers, and regist rars. Br Med J 312: 1340- 1344
[ 11] Dash A ( 2009) Lost + found: m aking t he right choice in equipm ent locat ion syst em s. Healt hc Facil Manag 22( 11) : 19- 21
[ 12] De Vries G, Bert rand JWM, Vissers JMH ( 1999) Design requirem ent s for healt h care product ion cont rol syst em s. Pr od Plan Cont rol 10: 559- 69
[ 13] Delesie L ( 1998) Bridging t he gap bet w een clinicians and healt h m anagers. Eur J Oper Res 105( 2) : 248- 256
[ 14] Glouberm an S, Mint zberg H ( 2001a) Managing t he care of healt h and t he cure of disease - part I : different iat ion. Healt h Care Manag Rev 26: 56- 69
[ 15] Glouberm an S, Mint zberg H ( 2001b) Managing t he care of healt h and t he cure of disease - part I I : int egrat ion. Healt h Care Manag Rev 26: 70- 84
[ 16] Graves SC ( 2002) Manufact ur ing planning and cont rol. I n: Pardalos P, Resende M ( eds) Handbook of applied opt im izat ion. Oxford Universit y Press, New York: 728- 746
[ 17] Grol R, Giesen PHJ, van Uden C ( 2006) Aft er - hours care in t he Unit ed Kingdom , Denm ark, and t he Net herlands: new m odels. Healt h Affairs 25( 6) : 1733- 1737
[ 18] Hans EW, Herroelen WS, Leus R, Wullink G ( 2003) A hierarchical approach t o m ult i- proj ect planning under uncert aint y . Om ega 35( 5) : 563- 577
[ 19] Hax AC, Meal HC ( 1975) Hierarchical int egrat ion of product ion planning and scheduling. I n: Geisler M ( ed) TI MS St udies in t he m anagem ent sciences: logist ics. Nort h Holland- Am erican Elsev ier, Am st erdam : 53- 69
[ 20] Johnson G, Scholes K, Whit t ingt on R ( 2008) Explor ing corporat e st rat egy, 8t h edn. Prent ice Hall, New Jersey
[ 21] Khoum bat i K, Them ist ocleous M, I rani Z ( 2006) Evaluat ing t he adopt ion of ent erprise applicat ion int egrat ion in healt h- care organizat ions. J Manag I nf Syst , 22( 4) : 69- 108
[ 22] Lat t im er V, Turnbull J, Burgess A, Surridge H, Gerard K, Lat hlean J, Sm it h H, George S ( 2005) Effect of int roduct ion of int egrat ed out of hours care in England: observat ional st udy. Br Med J 331( 7508) : 81–84
[ 23] Laudon KC, Laudon JP ( 2010) Managem ent inform at ion syst em s, 11t h edn. Prent ice Hall, New Jersey
[ 24] Li LX, Bent on WC, Keong Leong G ( 2002) The im pact of st rat egic operat ions m anagem ent decisions on com m unit y hospit al perform ance. J Oper Manag 20: 389- 408
[ 25] Marri HB, Gunasekaran A, Gr ieve RJ ( 1998) Com put er- aided process planning: a st at e of art . I nt J Adv Manuf Technol 14( 4) : 261- 268
[ 26] Maynard A ( 1991) Developing t he healt h care m arket . Econ J 101( 408) : 1277- 1286
[ 27] Maynard A ( 1994) Can com pet it ion enhance efficiency in healt h care? Lessons from t he reform of t he U.K. Nat ional Healt h Serv ice. Soc Sci Med 39( 10) : 1433- 1445
[ 28] Dat a from 2009 from t he w ebsit e of Organisat ion of Econom ic Co-operat ion and Developm ent ( OECD) ( 2009) ht t p: / / w w w .oecd.org/ healt h. Accessed 25 May 2010
[ 29] Operat ional Research Applied t o Healt h Services ( ORAHS) ( 2010) ht t p: / / w w w .m anagem ent .sot on.ac.uk/ ORAHS/ . Accessed 25 August 2010
[ 30] Orlicky J ( 1975) Mat erial requirem ent s planning. McGraw - Hill, London
[ 31] Ozcan YA ( 2009) Quant it at ive m et hods in healt h care m anagem ent – t echniques and applicat ions ( 2nd ed.) . Jossey- Bass/ Wiley, San Francisco, CA, pp 6- 9
[ 32] Port er ME, Teisberg EO ( 2007) How physicians can change t he fut ure of healt h care. J Am Med Assoc 297: 1103- 1111
[ 33] Rhyne D, Jupp D ( 1988) Healt h care requirem ent s planning: a concept ual fram ew ork. Healt h Care Manag Rev 13( 1) : 17- 27
[ 34] Rot h AV, van Dierdonck R ( 1995) Hospit al resource planning. Prod Oper Manag 4: 2- 29
[ 35] Van Uden CJ, Am ent AJ, Voss GB, Wesseling G, Winkens RA, Van Schayck OC, Crebolder HF ( 2006) Out - of- hours prim ary care. I m plicat ions of organisat ion on cost s. BMC Fam Pract 7( 1) : 29
[ 36] Vissers JMH ( 1998) Pat ient flow - based allocat ion of inpat ient resources: a case st udy. Eur J Oper Res 105: 356- 370
[ 37] Vissers JMH, Beech R ( 2005) Healt h operat ions m anagem ent . Rout ledge, London
[ 38] Vissers JMH, Bert rand JWM, De Vries G ( 2001) A fram ew ork for product ion cont rol in healt h care organizat ions. Prod Plan Cont rol 12: 591- 604
[ 39] Wacht el RE, Dext er F ( 2008) Tact ical increases in operat ing r oom block t im e for capacit y planning should not be based on ut ilizat ion. Anest h Analg 106( 1) : 215- 226
[ 40] West ert GP, Burgers JS, Verkleij H ( 2009) The Net herlands: regulat ed com pet it ion behind t he dykes? Br Med J 339: 839- 842
[ 41] Zij m WHM ( 2000) Tow ards int elligent m anufact uring planning and cont rol syst em s. OR Spect r 22: 313- 345
