AN INTERIM REPORT ON SOFT SYSTEMS EVALUATION Viljem Rupik INTERACTA, LTD, Busiess Iformatio Processig Parmova 53, Ljubljaa 386 01 4291809, e-mail: Viljem.Rupik@siol.et Abstract: As applicatio areas rapidly grow beyod the theoretical framework of fudametal decisio theory we are very ofte temptated to see whether or ot soft systems may promise some efficiet modellig of real life problems. The pioeerig bust towards soft systems methodology has come from the eeds of mathematical sociology. Its cotemporary defiitio as well as its applied architecture have bee dealt with as i a paper proposed. Key words: fudametal decisio theory, soft system modellig 1. AN INTRODUCTION The origial decisio theory offers the largest formulatio of decisio process, compresed through fudametal equatio of deciso theory (FDT). Sice it is a brute force approach, our followig its lies of implemetatio hits upo severe obstacles to satisfyig solutios (see /1/). The appearece of soft systems methodology (SSM) seems to be a way out of these troubles, despite may trappig states threateig the applicatio of FDT. To check whether or ot the SSM is some step of improved system modellig, we shall here match the two cocepts. As a whole, there are two sigificat ad crucial scietific areas which ifluece pragmatic reputatio of OR: goseology ad hermeeutics. They iteract strogly, especially whe SSM is beig exercised. Both of them should be take ito accout: the first oe determies the problem solvig procedure ad the latter oe shapes the scope ad depth of its implemetatio i real busiess lives. 2. BASIC CONCEPT OF SSM The most outstadig authors are Peter Checklad ad Jim Scholes (see /2/) which itroduce basic SSM cocept ad the possibility to coceive the potetial difficulties whe applyig it. Their book discloses various applicatios as variatios of the basic SSM cocept. They are as follow i pure verbal form: 43
a real world situatio of cocer yields of choices relevat systems of purposeful activity compariso of models with perceived real situatio actio eeded to improve the situatio 3. BASIC CONCEPT OF FDT To judge the SSM as it stads today we first have to reiterpret the above milig stoes i terms of geeral decisio theory (FDT), which we reproduce as follows. To illumiate it, let us start with geeral decisio theory ad its fudametal equatio, whose costituets are as follows: - let X be a arbitrary fiite dimesioal vector space, represetig all coceivable decisio variables x X ; let be a object of decisio makig process (which, i geeral, is ot a problem itself); - there is always at least oe cosequece y Ym, agai from fiite dimesioal vector space, correspodig to iput x X ; - we also itroduce a operator Y = SX producig output from iput; let us call it as decisiogeerator; - X a should serves as a space of admissible decisio variables, X a X ; - let z Z be a estimate of a cosequece of decisio variable y Ym (of a arbitrary dimesio); - there is a mappig U of y Ym ito z Z ; - let q Q be a primary (backwards) costructio of a problem, based o, uder the coditios of certaity; - q~ ( z... z ) ~ Q as a aalogy, let q~ ~ Q be a secodary (backwards) costructio of the same 1, m problem, based o, uder the coditios of ucertaity; 44
- let is a mapppig of Y ito Q ( a primary geerator of problem costructios); i real situatios, this mappig reduces Q ito some part Q ; - for the case of ucertaity, let maps Z ito Q ~ ; here agai, this mappig may produce some shrikage of Q ~ ; - the shrikage of Q ~ is the projected oto Z * Z via operator ; - is a operator of iduced subspace X * d Z * Z ; of alterative admisible decisios, beig mapped from Based o these miimal categories of FDT processig the followig graph might be useful (see/1/): X X d X * d S y Y m U Z Z* Q? Q ~ Q ~ Q ~ Q ~ 3. SSM-FDT MATCHING Now, the matchig is ow as follows: A real world situatio of cocer may be iterpreted as q~ ~ Q strictly i FDT sese although is ot defied ad expressed explicitly; cosequetly, SSM is»dealig«with ; yields of choices may be iterpreted as z, where z Z accordig to (FDT); 45
Z* oly teds to be reached; cosequetly, is ot formalised, at least ot at each step of approximatio; relevat systems of purposeful activity might be roughly iterpreted by U, igorig y Ym ; compariso of models with perceived real situatio could be coceived by a pair of, but Q ~ ad Q ~ are ot explicitly computed; actio eeded to improve the situatio could be uderstood as although SSM is ot explicitly stemmig from Q ~ ; cosequetly, Z* ca ot be reached strictly; q Q is ot ivolved i SSM ad, cosequetly, it ca ot serve as a basis for Q ~ ad Q ~ : costructio parameters describig do ot appear; by SSM approach, a fact which worries most of all is that the perceptio of a) uderlies a subjective decriptio/perceptio ad b) chages over a series of approximatios; cosequetly, it is difficult to expect the procedure to be coverget; withi the FDT framework we usually simplify»our«space of cosequeces to be Z=(US)X ad thus X= ( US) 1 Z (if possible?!), ad cosequetly US 1 : it meas that a) we eglect ay alterative solutios, b) we eglect admissible solutios, c) we are too bold to assume that all iputs could be solutios; withi the SSM framework these questios are still more obscure: i case of FDT the questio is whether S is kow to us; it is the same with SSM case; operator U is questioable i both cases either; the two operators U ad S i FED are tacitly assumed to be ucertai: do we use it i a SSM case (or as determiistic operators)? i FDT case: are we sure that Q ~ is sufficiet for our decisio o X * d? What about SSM case? a similar doubt as to the operators U ad S to hold true for all other operators i FED as well as i SSM case ; a trasitio from Q to Q ~ has ot bee examied whatsoever; it has bee a reflectio of our dagerous oversimplificatio of FDT decisio proces; a bridge betwee hard ad soft scieces is ofte demolished by usig U= idetity operator which is, i geeral, very far from beig realistic ad adequate approach; it may well hape that a/the solutio y Ym is acceptable from techical aspects oly, but ot from the others; i FDT case where we are ot worried about makig some adequate sapshots of to get problem space Q, or, eve worse, Q ~? How about SSM case? 46
As we may coclude, it is ot possible to derive the fudametal equatio of decisio theory (FED): X * d ( US) X as a couterpart to SSM. 4. EXAMPLES ON SOME REAL LIFE PROJECTS There have bee several projects at the earest past which iduced our tempatio to exercise SSM approach. To exhibit some most importat features we chose the three projects: A: The miimal methodology of maagemet ad cotrol of agriculture developmet i Sloveia (see /3/); B: Network ecoomics modellig o electroic data iterchage, developed for ATNET (Advaced techoilogy etwork) (see /4/); C. The aalysis of New York Stock Exchage operatios (see /5/) The reappraisal of the above projects had bee focused i the light of SSM-FDT compariso. The mai fidigs are listed below resultig project A project B project C features closer to SSM fully FDT defied well FDT defied Q large dimesioal FDT space, stochastic small dimesioal FDT space, stochastic variable modest dimesioal FDT space, y Y m stochastic, closer to SSM space ad stochastic o-formal operators (see /8/) stochastic FDT space determiistic FDT operators stochastic ot defied stochastic FDT operators loose looped feedback stochastic FDT operators mild stochasticity operator (see /6/) Q ~ partitio subject to iteractio aalysis partitio arbitrary fixed SSM coditioal partitio X * d o observability o observability o observability Z* cotrollabilty via Q ~ suspected of wild stochasticity, of SSM type fully eabled, of FDT type mild stochasticity space, of FDT type U requires fluid modellig (see /7/) piecewise determiistic fuctioal o-existig 5. A PARTIAL CONCLUSION It follows from the examples above that either SSM or FDT is apt to serve as a complete ad satisfactory device of modellig. Each of them should somehow be modified to offset the real situatio. Modificatios are expected to take place at differet costituets of each particular type of modellig discussed above. 47
REFERENCES /1/ Rupik V., (2005),»O Some Trappig States to OR«, Proceedigs of the 8th Iteratioal Symposium o OR, Nova Gorica, Sloveia, Sept.28-30., pp. 23-36. /2/ Checklad P. ad Scholes J., (1990), Soft Systems Methodology i Actio, J.Wiley &Sos. /3/ Rupik V., (2006),»The miimal methodology of maagemet ad cotrol of agriculture developmet i Sloveia«, project proposal to Chamber of Agriculture ad Forestry, Sloveia. /4/ Rupik V.,(1995),»Network ecoomics modellig o electroic data iterchage«, project developed for ATNET (Advaced techology etwork), Koper, Sloveia. /5/ Rupik V.,»The aalysis of New York Stock Exchage operatios«, project beig developed for INTERACTA, Busiess Iformatio Egieerig, Ljubljaa, Sloveia, sice 2002 o. /6/ Volcjak R., (2000),»Applicability Limits to the Quality of Ecoomic Modellig«, PhD thesis, Departmet of Ecoomics, Uiversity of Ljubljaa. /7/ Rupik V., (1985),»Some Experieces with Fluid Modellig of Ecoomic Systems«, Systems Research, The Official Joural of the Iteratioal Federatio for System Research, Vol. 2, No.3, pp.211-219. /8/ Rupik V., (1997),»A Attempt to No-Formal Modellig«, Proceedigs of the Fourth Iteratioal Symposium o Operatioal Research, Preddvor Sloveia, Oct.1-3 1997, pp.207-213. 48