Performance Assessment Modelling for the Integrated Management System in Construction Projects

Transcription

1 European Journal of Scentfc Research ISSN X Vol.29 No.2 (2009), pp EuroJournals Publshng, Inc Performance ssessment Modellng for the Integrated Management System n Constructon Projects mruddn Ismal Sustanable Urban Transport Research Centre Department of Cvl and Structural Engneerng Faculty of Engneerng and Bult Envronment Unverst Kebangsaan Malaysa (UKM) UKM Bang, Selangor Darul Ehsan, Malaysa E-mal: abmsmal@gmal.com Tel: ; Fax: bbas M bd Department of Cvl and Structural Engneerng Faculty of Engneerng and Bult Envronment Unverst Kebangsaan Malaysa Zamr Chk Department of Cvl and Structural Engneerng Faculty of Engneerng and Bult Envronment Unverst Kebangsaan Malaysa Muhammad Fauz Mohd. Zan Department of rchtecture, Faculty of Engneerng and Bult Envronment Unverst Kebangsaan Malaysa bstract The most approprate tools to manage the uncertanty and vagueness of the qualty performance n constructon projects are the Qualty Management and Envronmental Management systems. Because of the benefts of ther nteracton, the two systems were ntegrated to formulate the Integrated Management System (IMS). Qualty performance has been assessed to montor the constructon processes and actvtes status. The developed Evaluatng System has been utlzed dfferent assessment crtera, sub-crtera, and ther combnatons. The concepts of fuzzy set theory have been ntroduced to represent the uncertanty and vagueness of each qualty requrements. The study context s lmted to constructon projects to pont out the usng of these concepts for analyzng and mprovng the qualty culture n ths sector. The fndngs reflect the relatve sgnfcance and the probablty of fal for each artcle of the system components, the ablty of ntegraton for two systems or more, and some recommendatons were suggested for further development.

2 Performance ssessment Modellng for the Integrated Management System n Constructon Projects 270 Keywords: Envronmental System, Integraton Management, Qualty System, Constructon Management 1. Introducton One of the most sgnfcant ssues facng today s constructon ndustry s the achevng of customer satsfacton. Ths perspectve reflected from the mportant role played by customer as the core of the constructon ndustry and the drvng force for mprovement. The satsfacton process s defned as the process runnng throughout the constructon project by whch means the project requrements are progressvely captured and translated nto effect. Because of ts pvotal role n elctng and communcatng customer requrements to the desgn and constructon teams, the satsfacton process s a cornerstone for achevng goals. Hence, t has to be flexble, well organse and responsve to the customer requrements (Othman et al., 2004). Formal observatons, lterature revew, experence analyss of 97 constructon related experts, documentary data, questonnare and unstructured ntervews wth projects' team undertaken by the author showed that very few buldngs are fnshed on tme, or at the rght cost and customer (clents) often blame the constructon ndustry of provdng products that do not acheve ther requrements and meet ther expectatons. Furthermore, customers artculated that they used change orders to acheve ther expected requrements and to adapt to the nfluence of the nternal and external rsks. Ths s attrbuted to the lmtatons of the current project management approaches, whch confne the development of the project processes to a certan stage. Ths perspectve hnders the nteracton between the project partes and processes, and mpedes explotng value opportuntes and managng rsk threats n all project s processes. In order to overcome the lmtatons of the current brefng approaches, the Integrated Management System s concept was developed. Ths concept supports and encourages the development of decson makng process throughout the project lfe cycle as an approach to acheve customer satsfacton and respond n an nnovatve manner to the performance mprovement, and to manage change orders effectvely (Othman et al., 2004). Developng such system wthout establshng the procedures that control ts processes development leaves the project management uncontrolled and jeopardse achevng clent s satsfacton. Because such system development can add value or rsk to the project or could add both, the well-establshed methodologes of Qualty Management (QM) and Envronmental Management (EM) are the most approprate tools to manage project performance. Ths paper ams to establsh the bass and set the rules for ths approach, and develop the tool that wll manage and control qualty performance n constructon projects. Two objectves were developed to acheve ths am. The frst one s theoretcal, whch focused on utlzng the role of QM and EM n managng qualty performance. The second objectve s practcal whch presents an nnovatve decson makng tool, developed by the author that wll be used n the process of makng an approprate decson, assessment and as tranng tool for the project staff. 2. Integraton of Management Systems Tradtonally, an organzaton would mplement ts management systems one at a tme, wth ther boundares remanng clear-cut after the mplementaton process to hghlght ther mportance to employees. s a result, however, solaton among management systems and wth the overall busness management s most lkely to happen, hnderng the chances to acheve some of the expected benefts and creatng new problems of ts own. Waste of resources, conflcts of nterest, sub-optmzaton of local goals n opposton of overall goals, repetton of actvtes, ncreasng paperwork, confuson on prortes and objectves and a general lack n achevng the organzaton's objectves may be some of the problems created by ths lack of connectvty among functonal management systems that have been mplemented usng standards.

3 271 mruddn Ismal, bbas M bd, Zamr Chk and Muhammad Fauz Mohd. Zan Ths lack of ntegraton between management systems has been recognzed by researchers, practtoners and standards developers, mostly from the qualty feld, resultng n dfferent ntatves to counteract t (Karapetrovc et al., 1998; Wlknson et al., 1999). For nstance, MS standards for qualty (ISO 9001:2000), and envronment (ISO 14001:2004) have been made more compatble wth each other. lthough some work has been done for the ntegraton of management systems, further work s stll requred, both conceptual and emprcal. The most pressng need, dentfed by Jonker et al., 2004, s to develop a model for the ntegraton of management systems along wth a supportng methodology for ts mplementaton. ddtonal consderatons to be ncluded n both the model and the methodology are: Dfferent startng ponts to buld upon, e.g. an ISO 9001 QMS or an ISO EMS or none at all. Dfferent sequences of ntegraton, e.g. an IMS coverng qualty and envronmental requrements may be mplemented by ntegratng QMS frst and EMS later or an EMS frst followed by a QMS. Dfferent fnshng ponts accordng to organzaton's own needs, e.g. an IMS ncludng qualty, envronmental and occupatonal health and safety requrements. The need for engagng stakeholders nto the systems to optmze the organzaton's performance; Level of ntegraton of functonal standardzed requrements wthn the IMS, e.g. algnment or harmonzaton (Karapetrovc et al., 2002). udtng, evaluaton, control and mprovement of an IMS (Dale, 2004). These consderatons are mssng n the exstng models developed to ntegrate management systems, thus motvate to create the approach of ths research. Havng two or more Management Systems mplemented n a sngle organzaton could ncrease the rsk an organzaton has of actually havng these problems. Furthermore, certan problems have been dentfed as the result of solaton between MS s bult based on standards. Throughout the lterature, a lst of problems derved from such solaton has been dentfed mostly referred to solaton between QMS and EMS (Corcoran, 1996; Karapetrovc et al., 2002; Wlknson et al., 2002): Waste of resources. Conflcts of nterest and confuson n prortes and goals. Repetton of actvtes and processes. Increasng paperwork. Lack of commtment towards the MS from top management. Endng up wth dssatsfy stakeholders nonetheless for lack of performance. n alternatve to overcome solaton among standardzed management systems and ts correspondng problematc s the ntegraton of standardzed management systems. 3. Fuzzy pproach to IMS Representaton To deal wth vagueness of human thought, Zadeh (1965) frst ntroduced the fuzzy set theory, whch was orented to the ratonalty of uncertanty due to mprecson or vagueness. major contrbuton of fuzzy set theory s ts capablty of representng vague data. The theory also allows mathematcal operators and programmng to apply to the fuzzy doman. fuzzy set s a class of objects wth a contnuum of grades of membershp. Such a set s characterzed by a membershp (characterstc) functon, whch assgns to each object a grade of membershp rangng between zero and one. The parameters m1, m2 and m3 respectvely denote the smallest possble value, the most promsng value, and the largest possble value that descrbe a fuzzy event. Each Trangular Fuzzy Number has lnear representatons on ts left and rght sde such that ts membershp functon μ can be defned as:

4 Performance ssessment Modellng for the Integrated Management System n Constructon Projects x m1 ( x m1) /( m2 m1)... m1 x m2 μ = ( m3 x) /( m3 m2)... m2 x m3 (1) 0... x m3 fuzzy number can always be gven by ts correspondng left and rght representaton of each degree of membershp as explaned n Fgure 1. Fgure 1: Fuzzy trangular number representaton (x) 1 0,0 M1 M2 M3 X Fuzzy sets were frst ntroduced to elucdate the concept of fuzzness. Fuzzy sets represent lngustc varables whose values are not numbers, as for numercal varables, but are words or sentences n a natural or artfcal language (Zadeh 1965). The mx desgn nvolves a complex and nonlnear procedure that s nfluenced by the materal nteracton and culture of constructon qualty. Hence, t s dffcult to develop a comprehensve analytcal model by consderng all desgn varables. Typcally, concrete mx companes have extensve records of ther past mx proportons, whch can be used to develop a model for the desgn procedure. s shown n Fgure 1. fuzzy set can be defned mathematcally by assgnng to each possble element n the unverse of dscourse a value representng ts degree of membershp n the fuzzy set. Ths means that, contrary to the classcal sets theory n whch an element ether belongs to or does not belong to a set (.e. ts membershp to that set s crsp), n fuzzy sets theory the belongng of an element x to a set s defned by a degree of membershp ndcated by a number n the nterval [0,1]. Hence, the fuzzy set can be defned by a set of ordered pars, a bnary relaton, as follows (Bojadzev et al., 1997): = (2) where μ (x) s the membershp functon that specfes the degree to whch any element x n belongs to the fuzzy set. Defnton (2) assocates wth each element n a real number μ (x) n the nterval [0,1] whch s assgned to x. Larger values of μ (x) ndcate hgher degrees of membershp. In general, the fuzzy set can be expressed by m dscrete values, μ (x) as follows: = [ x1 μ ( x1 ), x2 ( x2 ), x3 μ ( x3),... xm μ ( xm )] (3) Propertes of fuzzy sets are brefly ntroduced as follows: normalzed fuzzy set s one that ncludes at least one element x0 n the unverse of dscourse that attans the maxmum degree of membershp, that s μ ( x 0 ) = 1 ; otherwse the fuzzy set s called non-normalzed. For example, all fuzzy sets n Fgure 1 are normal as they have at least one element x wth a degree of membershp equal to l.

5 273 mruddn Ismal, bbas M bd, Zamr Chk and Muhammad Fauz Mohd. Zan α -level nterval or α -cut, denoted by α, s defned as the crsp set of elements x whch belong to at least to the degreeα. It gves a threshold that provdes a level of confdence α n a decson or concept modelled by a fuzzy set. The threshold may be used to dscard from consderaton those element x n wth degrees of membershp μ ( x 0 ) < α. Ths can be expressed as: α = { x x R, μ α}, x [0,1] (4) Operatons on fuzzy sets, whch are relevant to ths research work, nclude the ntersecton and unon of two or more fuzzy sets. The operatons wth fuzzy sets and B n the unverse U are ntroduced va operatons on ther membershp functons μ (x) and μ (x) B, as follows: a) Intersecton of fuzzy sets and B denoted as B s defned by μ = mn( μ x μ x x μ B ( ), B ( )), (5) The ntersecton of two fuzzy sets s related to the conjuncton (logcal operator ND) n fuzzy logc. For nstance, f a1< a2, mn (a1, a2) = a1; ths s, mn (0.5, 0.7) = 0.5. b) Unon of and B denoted as B s defned by: μ = max( μ x μ x x μ B ( ), B ( )), (6) The unon of two fuzzy sets s related to the logcal operaton of dsjuncton (OR) n fuzzy logc. For nstance, f a1< a2, max (a1, a2) = a2; that s, max (0.5, 0.7) = 0.7 c) Complementaton of the fuzzy set s f the followng condton s true: μ = 1 μ μ + = 1 or μ (7) The complement of a fuzzy set s related to the logcal operator NOT n fuzzy logc and ts μ (x) membershp functon s symmetrcal μ (x) wth respect to μ = Modellng the Evaluatng System The man features of ISO 9001: 2000 are; process approach to system; process measurement and management; customer satsfacton montorng; and contnual mprovement, ISO 9001: 2000 also places a stronger emphass on the qualty management functon of the organzaton as dstnct from qualty assurance and qualty control actvtes and thus s very clear for the fve requrements. The ISO seres consst of fve standards: Envronmental management systems, envronmental audtng, envronmental labellng, envronmental performance evaluaton and lfe cycle assessment. ISO 14001: 1996, an envronmental management standard aganst whch an organzaton can be audted on a voluntary bass, s applcable to dfferent organzatons n dverse geographcal, cultural and socal condtons. The other standards n the ISO seres provde gudelnes whch ether support the mplementaton of an EMS or the analyss of product characterstcs. None of these other standards need to be mplemented. ISO 14001: 1996 provdes a structured management system to enable constructon frms to acheve benefts that would enhance the organzaton s mage and credblty (Tan et al., 1998). The major elements and requrements of ISO 9001: 2000 are: Qualty management system: General requrements and documentaton requrements; Management responsblty: Management commtment, customer focus, qualty polcy, plannng, responsblty, authorty and communcaton, and management revew; Resource management: Provson of resources, human resources, nfrastructure, and work envronment; Product realzaton: Plannng of product realzaton, customer related processes, desgn and development, purchasng, producton and servce provson, control of montorng and measurng devces; and Measurement, analyss and mprovement: General, montorng and measurement, control of nonconformng product, analyss of data, and mprovement.

6 Performance ssessment Modellng for the Integrated Management System n Constructon Projects 274 The major elements and requrements of ISO 14001: 1996 are: Envronmental polcy. Plannng. Envronmental aspects: Legal and other requrements, objectves and targets, and envronmental management programs. Implementaton and operaton: Structure and responsblty, tranng, awareness and competence, communcaton, EMS documentaton, document control, operatonal control, and emergency preparedness and response; and Checkng and correctve acton: Montorng and measurement, non-conformance and correctve and preventve acton, records, audt, and management revew. rsng from the fve man qualty management system requrements, ISO 9001:2000 and the four man requrements of envronmental system ISO 14000:1996; the ntegrated management system have been establshed to provde a unque document that can be appled for the dfferent goals. The dfferent levels of system artcles are shown n Fgure 2. Fgure 2: Man and sub-tems of IPM system In order to accommodate the dverse range of expressons and human dfferences n nterpretng the degree to whch any system component s avalable, sgnfcance, probablty, the avalablty unverse (), defned as a fuzzy set, has values rangng from zero to one, correspondng to eleven possble values. These values are (very low, low, average, hgh, and very hgh). These functons are represented by the translatonal/trangular models where every lngustc term s represented by sosceles trangles as shown n Fgure 3-a, 3-b and 3-c respectvely. The frst requrement (System setup and documentaton) and second one (System management) have been represented by the model n Fgure 3-a, whch reflect hgh vagueness degree. The nteracton between levels s hgh due to the hgh degree of uncertanty for the artcles under these two tems. Meanwhle; thrd Items (Resources management) and fourth (Requrement realzaton), are represented by the second model whch have least degree of vagueness, t can seen from the small area of nteracton between the fve levels of

7 275 mruddn Ismal, bbas M bd, Zamr Chk and Muhammad Fauz Mohd. Zan assessment, Fgure 3-b. The ffth requrement (montorng and mprovement) has been represented by ntermedate scale as shown n Fgure 3-c. The three scales of representaton (3-a, 3-b, and 3-c) reflect the degree of confdence of the experts wth the assessment that can be provded by the project staff or qualty assessors. Fgure 3: The three models for represent the IMS system One of the features of ths representaton s that the fuzzy set can be smply represented by a numercal nterval. For example the fuzzy set average () n Fgure (3-a) can be wrtten as: avalable = { , , , , , , , , , , } Followng Equaton (3), or smply as avalable = [3.0, 7.0], whch s the base of the sosceles trangle. Ths feature s a result of the form of the fuzzy set. Snce sosceles trangles are used, dentfyng the locaton of the trangle s base through a numercal nterval s suffcent to draw the complete fuzzy set. The second varable, sgnfcance (S), s also represented by a trangular fuzzy set, and can take values rangng from 0 to 1 (Kashwag, 1995). These values are determned by a system expert as dscussed earler. The expert s knowledge and experence lngustcally evaluate the mportance or sgnfcance of every system component to the overall Integrated Management System Performance (IMS). The objectve of ths representaton s to combne the dfferent system components. Ths

8 Performance ssessment Modellng for the Integrated Management System n Constructon Projects 276 combnaton s necessary to obtan the overall system performance. The overall System performance (QSP) s found usng equaton (8): ( S ) Sgnfcance of IMS = S (8) In whch IMS = Total Integrated Management System Performance, = ndvdual avalablty of each system component, and S = sgnfcance of a partcular system component. Ths equaton, whch s normally referred to as the fuzzy average functon, s an aggregaton functon n whch dfferent components are combned to produce a fnal sngle result. ccordng to Zadeh s extenson prncple, the mathematcal operatons on fuzzy sets should follow a specal procedure. The extenson prncple extends the bnary operaton (X) of real numbers to fuzzy sets (Caballero et al., 1999). ccordngly, the arthmetc of fuzzy sets can be derved n the followng manner: μ( * B) = [ μ μ B ] (9) Where {*=(+,-,x,/); =mnmum, and =maxmum}. Thus the multplyng and dvson operators used n Equaton (8) are replaced by ther counterparts lsted n Equaton (9). Note that the fuzzy sets wll present by numercal ntervals as shown earler. Ths representaton, although shortened, does n fact carry all the nformaton n the extended form of the fuzzy set representaton. The next secton llustrates the evaluaton method of the dfferent components of the Integrated Management System Performance (IMS) usng the dfferent arthmetc of fuzzy sets dscussed n ths secton. To calculate the component Establsh IPM system, an element of IPM system, one needs to evaluate all the unts comprsng t (Eq. 10). 11 performance = ( 11 S11 ) / S11 (10) What should be noted here s that the above equaton s a fuzzy composton equaton that corresponds to Equaton (10). [ ( 11 S11 ), ( 11 S11 )] 11performance = S11 (11) Where = the mnmum, and = the maxmum. For Equaton (11) 11 corresponds to the dfferent unts of the (Establsh IPM system) performance (Table 2). Each 11 s a lngustc term that corresponds to the degree to whch every unt of the Establsh IPM system s avalable, and S11 corresponds to the sgnfcance of the unt to the total Establsh IPM system performance. s mentoned earler, both fuzzy sets are presented by sosceles trangles that are better descrbed usng numercal ntervals. The database collected from the experence of partcpants for the sgnfcance of requrements and the probablty of fal for both the qualty and envronmental system are presented n Table 1 and 2 respectvely.

9 277 mruddn Ismal, bbas M bd, Zamr Chk and Muhammad Fauz Mohd. Zan Table 1: Organzaton qualty system: sgnfcance and probablty of fal No. Sub-Item Sgnfcance Probablty of fal From To vg. From To vg. 1 Establsh IPM System Documentaton System Strategc process Scope & Customer Focusng Rsk Related Process Leadershp and Cooperaton Process & System pproach Management Revew Resources Related Process Personnel Related Process Scope Related Process Purchasng Related Process Procurement Related Process Tme Related Process Cost Related Process Communcaton Related Process Progress and measures Control and mprovement Montorng and nalyss Contnual Improvement Table 2: Envronmental system: sgnfcance and probablty of fal No. Sub-Item sgnfcance Probablty of fal From To vg. From To vg. 1 Establsh IPM System Documentaton System Strategc process Scope & Customer Focusng Rsk Related Process Leadershp and Cooperaton Process & System pproach Management Revew Resources Related Process Personnel Related Process Scope Related Process Purchasng Related Process Procurement Related Process Tme Related Process Cost Related Process Communcaton Related Process Progress and measures Control and mprovement Montorng and nalyss Contnual Improvement n example for the calculatons of the qualty performance assessment for resources management artcle was presented n Table 3. The fourth column of the table lsts the values of multplyng valablty () by Related Sgnfcance (S), whch represents the numercal nterval that corresponds to the mnmum and maxmum.

10 Performance ssessment Modellng for the Integrated Management System n Constructon Projects 278 Table 3: The ntegrated management system: resources management calculaton Resources Management Sgnfcance S valablty S Mn Max Mn Max Mn Max Resources Related Process Personnel Related Process Scope Related Process Purchasng Related Process Σ S Σ ( S) The overall performance for ths element s calculated usng Equaton (10): ( 11 S11 ) (93.27,222.69) 11 performance = = = (4.23,6.68) S (22.04,33.34) 11 The nterpretaton of ths numercal nterval can easly be done by mposng the sosceles trangle, whose base corresponds to t on the membershp values graph n Fgure 4. Ths process yelds one component performance between verage and Hgh but t near to verage. Fgure 4: Membershp graph for resources management Fgure 5: Sgnfcance, avalablty and probablty of fal for resources management elements

11 279 mruddn Ismal, bbas M bd, Zamr Chk and Muhammad Fauz Mohd. Zan From Fgure 5 the correlaton between the probablty of rsk setup by the experts and the shortage of avalablty of the IMS requrements can conclude. On the other hand, the relaton between the degree of sgnfcance and the avalablty of the requrements can be examned for each artcle and for the whole system. 5. Summary, Concludng Remarks and Recommendatons The outcome of ths research provdes contrbutons n several areas. t a global level, ths research work has developed a unque methodology for modellng project qualty performance ntegratng wth the envronmental requrements n constructon projects. The knowledge and experences have been modelled usng fuzzy set theory for a powerful analyss technque. The followng are sgnfcant aspects of the contrbutons of the ntegraton process acheved n ths research: Identfyng the sgnfcance and fal probablty for all tems wthn the IMS system, and explan the most sgnfcance and the crtcal fal probablty are for the system. Provde a mathematcal approach; usng fuzzy logc, to model the system and to create a numercal assessment approach that reduce the vagueness of usng the lngustc term n the qualtatve assessment up today. Mtgate waste of resources, duplcaton of documentaton and confuson of prortes due to havng two or more solated management systems wthn an organzaton whle stll satsfyng the stakeholders' needs. Possble reducton n audt fees as well as admnstratve costs of mplementaton and mantenance compared wth solated systems. Potental to be modfed to address new requrements wthn the same system. way to acheve "world class" status or to buld nto the success of organzatons' current systems. Improvement of understandng and use of the system by everyone wthn the organzaton Provdes drecton and structures for the busness to acheve standards n optmum costs. Provdes a strong foundaton towards a learnng organzaton through the mplementaton of two or more management systems and ther ntegraton, regardless of the fnal level or extent of the resultng ntegrated system. It s recommended, for further development, to study the potental rsks resultng from the ntegraton process tself, also, how to counterbalance the effect of these rsks on the fnal performance. However, an organzaton should decde what s the best for them before embarkng n such an endeavour. The IMS Scope, level of ntegraton, use of resources and tmeframe for mplementaton are aspects an organzaton should decde based on ts partcular condtons of sze, type, market, technology requred and management experence. Expert system Utlzng the mathematcal approach of ths research s also recommended to ease the applcaton of such system n the ste.

12 Performance ssessment Modellng for the Integrated Management System n Constructon Projects 280 References [1] Othman,..E., Hassan, T. M., and Pasqure, C.L. (2004) Drvers for Dynamc Bref Development n Constructon. Engneerng, Constructon and rchtectural Management. 11(4): DOI: / [2] Karapetrovc, S. and W. Wllborn, Self-audt of process performance. Internatonal Journal of Qualty & Relablty Management. 19(1): DOI: / [3] Karapetrovc, S. and W. Wllborn, Integraton of qualty and envronmental management systems. The TQM Magazne, 10(3): DOI: / [4] Wlknson, G. and B.G. Dale, n examnaton of the ISO 9001:2000 standard and ts nfluence on the ntegraton of management systems. Producton plannng & control, 13(3): DOI: / [5] Wlknson, G. and B.G. Dale, Integrated management systems: an examnaton of the concept and theory. The TQM Magazne, 11(2): DOI: / [6] Internatonal Organzaton for Standardzaton (ISO) ISO 9001:2000, Qualty Management Systems-Requrements. Geneva: ISO. [7] Internatonal Organzaton for Standardzaton (ISO) ISO 14001:1996, Envronmental Management Systems-Requrements. Geneva: ISO. [8] Jonker, J. and S. Karapetrovc, Systems thnkng for the ntegraton of management systems. Busness Process Management Journal, 10(6): DOI: / [9] Dale, B. G., Self-ssessment, Models and Qualty wards. Managng Qualty, Oxford, Blackwell Publshers. [10] Corcoran, I., One goal, one standard. Qualty World Journal, 22(10): [11] Tan, T. K., Ofor, G., and C. Brffett, ISO 14000: Its relevance to the constructon ndustry of Sngapore and ts potental as the next ndustry mlestone. Constructon Management Economc, 17(4): DOI: / [12] Kashwag, D., T., Usng Fuzzy Logc and the Management of Informaton to Increase the Performance of Constructon Systems. SC Proceedngs of the thrty frst nnual conference. [13] Caballero,.. and J. Dye, Comparson of Constructon Frms Based on Fuzzy Sets. SC Proceedngs of the thrty ffth nnual conference. [14] Zadeh, L. (1965). Fuzzy sets. Informaton and Control, Vol. 8, pp