An Integrated Control System for SMEs in the Construction Industry

4 ]Re is a de la Cons ucción Volumen 8 No 2 - 2009 Sis ema de Con ol In eg ado pa a PYMES del sec o de la Cons ucción An In eg a ed Con ol Sys em o SMEs in he Cons uc ion Indus y Au o es PELLICER, E. P o eso Ti ula Uni e sidad Poli écnica de Valencia, Escuela Técnica Supe io de Ingenie os de Caminos, Canales y Pue os, España email: [email p o ec ed].es Fecha de ecepción Fecha de acep ación 12/06/2009 07/08/2009 PELLICER, T. M. P o eso Con a ado Doc o Uni e sidad Poli écnica de Valencia, Escuela Técnica Supe io de Ingenie os de Caminos, Canales y Pue os, España email: [email p o ec ed].es CATALÁ, J. Ca ed á ico Uni e sidad Poli écnica de Valencia, Escuela Técnica Supe io de Ingenie os de Caminos, Canales y Pue os, España email: [email p o ec ed].es páginas: 4 - 17 [ 5 Re is a de la Cons ucción Volumen 8 No 2 - 2009 [ Pellice E. - Pellice T. M. - Ca alá J. ] Mos cons uc ion companies a e small and medium-sized en e p ises (SMEs) ha manage p ojec -based and business- ocused ac i i ies simul aneously. Comme cial so wa e packages a e no ully de eloped o o e a unique solu ion ha ackles bo h. To ill his gap, his pape desc ibes an in eg a ed managemen sys em speci ically de eloped o SMEs in he cons uc ion indus y, whe he con ac o s o consul ing enginee ing and a chi ec u al i ms. Bo h, p ojec and business unc ions a e add essed and handled by he sys em as a whole. Pa icula a en ion is gi en o he p ocu emen p ocess because i is essen ial o he s a egic planning o hese companies, which mus na u ally engage new con ac s o emain in business. The sys em is based on a clien / se e a chi ec u e ha is a anged in h ee ie s: p esen a ion (use in e aces La mayo pa e de compañías de la indus ia de la cons ucción son pequeñas y medianas emp esas (PYMEs) que ges ionan simul áneamen e ac i idades basadas en los p oyec os y en los negocios. Las aplicaciones in o má icas come ciales no se han desa ollado su icien emen e pa a o ece una solución única que abo de ambos aspec os. Con el in de cub i es a ca encia, el p esen e a ículo desc ibe un sis ema in eg ado de ges ión diseñado especí icamen e pa a PYMEs del sec o de la cons ucción, sean cons uc o as o consul o as de ingenie ía y a qui ec u a. Ambas unciones, p oyec uales y emp esa iales, son abo dadas y ges ionadas conjun amen e po el sis ema. Especial a ención o igina el p oceso de con a ación debido a que es undamen al pa a la plani icación es a égica de es as emp esas, las cuales deben consegui nue os con a os con el in de man ene se en el me cado. El sis ema es á basado en una a qui ec u a clien e/se ido que se es uc u a en and o ms), applica ion (que ies), and da a ( ela ional ables). The sys em uses MS AccessTM as a da abase managemen sys em. Use s a e ca ego ized acco ding o hei unc ions wi hin he hie a chy o he company, and he e o e se e al di e en in e aces a e designed o each pe sonnel ca ego y. The sys em wo ks in eal- ime, so e e y employee wi h a p e- es ablished igh o access can ob ain in o ma ion ins an aneously. This is c ucial o making immedia e decisions when p oblems a ise, allowing p omp ac ions om e e y manage in he hie a chy and esul ing in no ewo hy ime sa ings. This compu e -based applica ion has been success ully implemen ed by ou Spanish SMEs in he cons uc ion indus y. The sui abili y and ad an ages o he sys em implemen a ion a e highligh ed in his pape wi h speci ic da a ega ding i s cu en ope a ion. es ni eles: p esen ación (in e aces del usua io y o mula ios), aplicación (consul as) y da os ( ablas elacionales). Se u iliza MS AccessTM como sis ema ges o de la base de da os. Los usua ios se ca ego izan de acue do con sus unciones den o de la je a quía emp esa ial y, po lo an o, se diseñan di e en es in e aces pa a cada ca ego ía de pe sonal. El sis ema abaja en iempo eal, de modo que cada empleado, con sus de echos de acceso p ees ablecidos, puede ob ene in o mación ins an áneamen e. Es e aspec o es undamen al pa a oma decisiones inmedia as cuando su gen los p oblemas, pe mi iendo que los ges o es en cualquie ni el je á quico ac úen ápidamen e, y ob eniendo aho os de iempo sus anciales. Es a aplicación in o má ica se ha implemen ado con éxi o en cua o emp esas españolas del sec o de la cons ucción. La adap abilidad y en ajas del sis ema se des acan en el a ículo, incluyendo da os conc e os sob e su uncionamien o eal. Resumen Palab as cla e: Ges ión de negocios, emp esas cons uc o as, bases de da os elacionales, ecnología de la in o mación, adminis ación de p oyec os. Key wo ds: Business managemen , cons uc ion companies, ela ional da abases; In o ma ion Technology (IT), p ojec managemen . Abs ac [ 6 ]Re is a de la Cons ucción Volumen 8 No 2 - 2009 páginas: 4 - 17 Pellice E. - Pellice T. M. - Ca alá J. ] In oduc ion The cons uc ion indus y is managed p ima ily by p ojec s, on he one hand, and i is basically composed o small and medium-sized en e p ises (SMEs), on he o he . Fo each phase in he cons uc ion p ocess ( easibili y, design, cons uc ion, ope a ion, and di es men ), di e en kinds o p ojec s a e needed and, consequen ly, specialized p ojec -based companies ha e been se up o add ess his need (Gann and Sal e 2000; Winch 2006): mainly consul ing enginee ing and a chi ec u al (CEA) i ms and cons uc ion companies (con ac o s). Mos o hese companies can be conside ed as SMEs (DTI 1998; Pea ce 2003; Robei o and Lo e 2003) since, o ins ance, in he Eu opean Union he e is an a e age o i e wo ke s pe company ope a ing in he cons uc ion indus y (Eu os a 2006). Taking all hese in o accoun , many companies in he cons uc ion sec o manage hei business as a pool o p ojec s, ocusing on each p ojec in i sel (Engwall 2003). P ojec - ocused compu e ized ools ha e been de eloped o manage indi idual p ojec s and ensu e ha in o ma ion on he s a us o each p ojec is a ailable; ne e heless, hese ools ha e no been su icien ly de eloped o gua an ee good manage ial p ac ices no hey do p o ide a s a egic di ec ion o companies (Gann and Sal e 2000). Addi ionally, in o ma ion is no always sha ed among p ojec s and he bene i s o le e aging and in eg a ion a e ne e ealized (Engwall 2003). As a esul , hese companies usually look owa d business in eg a ion (Da enpo 1998). The e a e comme cial so wa e packages, gene ally called en e p ise esou ces planning sys ems (ERPs) ha can be implemen ed in any company om wha e e sec o . ERPs a e composed o a se o s anda d modules: p oduc ion, dis ibu ion, sales, human esou ces, accoun ing, inance, and so o h. These modules a e in eg a ed o allow all he depa men s o he company o wo k on he same compu e sys em, sha ing a common da abase. Addi ionally, ERPs aim o imp o e business e iciency p o iding accu a e in o ma ion on ime in o de o ake op imum decisions while diminishing he a ic o documen s among wo k pos s (Shi and Halpin 2003). Mos o he adi ional indus ial en e p ises and he la ge cons uc ion co po a ions ha e al eady implemen ed ERPs (Bo a-Genoulaz e al., 2005). Ne e heless, some au ho s ha e iden i ied wo basic p oblems wi h ERP sys ems. Fi s , he cos is ypically wo o six pe cen o he company’s annual u no e , conside ing no only he p ice o he so wa e, bu also i s implemen a ion and s a aining (Da enpo 1998; Shi and Halpin 2003; Ehie and Madsen 2005). Second, i is necessa y o adap he sys em o he o ganiza ional p ocesses and cul u e o he company and no he o he way a ound (Da enpo 1998; McA ee 2003; Ehie and Madsen 2005). Fu he mo e, he implemen a ion o ERP comme cial packages has been somewha disappoin ing as epo ed o SMEs (Huin 2004), he se ices sec o (Bo a-Genoulaz and Mille 2006), and he cons uc ion indus y (Shi and Halpin 2003). Following his end, Ta a i e al. (2007) ca ied ou a su ey among 101 cons uc ion companies (con ac o s, and CEA i ms) mos ly om he USA. They concluded ha only 4% o hese companies used ERPs o hei daily p ojec -based ac i i ies. Addi ionally, only 16% o he esponden s we e epo ed o be pleased wi h hei p esen le el o business in eg a ion. In b ie , comme cial so wa e packages o e limi ed solu ions o SMEs in he cons uc ion indus y. Some p o ide ope a ional ools (p ojec - ocused so wa e), bu no business managemen ools (company- ocused so wa e). By con as , ERPs a e gene ally sui ed o la ge-scale s anda d and epe i i e ope a ions and managemen p ocesses, jus he opposi e o wha p ojec -based i ms usually ace. Consequen ly, he main goal o ou esea ch is he de elopmen o an in eg a ed compu e -based managemen sys em, wo king in eal- ime, and speci ically designed o SMEs, aking in o accoun bo h p ojec ac i i ies and business ac i i ies ha ake place in e e y cons uc ion company. Acco dingly, his pape is s uc u ed as ollows. Fi s , he esea ch objec i es and he me hodology a e speci ied. Second is a e iew o he cu en esea ch as applied o he sec o . A model o business o ganiza ion is hen p oposed. Nex , he in eg a ed managemen con ol sys em is p esen ed and explained by means o some illus a ions. The echnical easibili y and ac ual implemen a ion o he sys em a e highligh ed la e . Finally, conclusions a e d awn and ecommenda ions o u u e esea ch a e made. Resea ch objec i es and me hodology We a gue ha e ec i e managemen o a ypical p ojec -based SME in he cons uc ion indus y equi es he a ailabili y o a lexible and easy o implemen compu e ized in o ma ion sys em speci ically designed o his kind o companies. The sys em mus deal wi h bo h p ojec -based and business- ocused ac i i ies. Ou pu pose is o desc ibe a compu e ized managemen sys em ha can be easily implemen ed in SMEs in he cons uc ion indus y in acco dance wi h hei cu en needs. This sys em is adap able and wo ks in eal- ime wi h a clien -se e a chi ec u e ha mee s he páginas: 4 - 17 [ 7 Re is a de la Cons ucción Volumen 8 No 2 - 2009 [ Pellice E. - Pellice T. M. - Ca alá J. ] equi emen s o hese companies. I uses cus omized applica ions o common comme cial so wa e. The e a e h ee addi ional objec i es o his s udy: • To e iew he cu en s a e o he a on he subjec . • To design and de elop a concep ual managemen model conside ing p ojec and business managemen ac i i ies. • To e i y he echnical easibili y o he sys em. The sys em desc ibed he ein is subjec ed o a ho ough heo e ical analysis as well as implemen a ion p ojec s o assess i s easibili y. The sys em is de eloped h ough a quali a i e analysis om di e en case s udies o Spanish cons uc ion i ms. The esul s a e ob ained om di ec obse a ion, in e iews and ollow-ups; hey a e he base o design he heo e ical and compu e models. Summa izing, he cases unde assessmen we e: • An e hnog aphic s udy o one medium-sized company ( om 1997 o he p esen ), which is specialized in ci il enginee ing design and cons uc ion managemen . • Th ee addi ional case s udies: one con ac o and wo CEA companies. • Se en in e iews wi h SMEs ( h ee con ac o s and ou CEA companies) ca ied ou in 2001 and 2002, wi h ollow-ups in 2003–2005, and 2007–2008. Li e a u e e iew Mo e han a decade ago, Rao e al. (1997) p oposed he use o in e connec ed componen s om comme cial so wa e ools as an al e na i e solu ion o de eloping a compu e ized managemen sys em. Thei p oposal consis ed o exclusi e, cus omized compu e applica ions assembled om o - he-shel so wa e packages. The in e connec ion o modules and p og ams, which a e gene ally amilia o he use , led o educ ions in de elopmen e o and aining (Rao e al., 1997). Following his cus omized applica ions philosophy, esea che s a he Cen e o In eg a ed Facili y Enginee ing (S an o d Uni e si y, USA) ha e wo ked o many yea s o de elop in eg a ed models o manage p ojec s in concu en enginee ing (see Kunz e al., 2002, o a summa y o hei wo k). Se e al cus omized sys ems o manage cons uc ion p ojec s ha e al eady been de eloped. All o hem we e c ea ed o p o ide solu ions a he p ojec managemen le el, wi hou aking in o conside a ion he managemen o he whole business. Abudayyeh e al. (2001) desc ibed an in ane -based cos con ol sys em capable o p oducing ins an epo s on demand, ocused on cos s gene a ed a he wo k si e. Elza ka (2001) sugges ed he in eg a ion o MS AccessTM, MS P ojec TM, and MS ExcelTM wi h Au oCADTM using isual basic echnology in o de o manage cons uc ion p ojec s du ing he design phase. Cheung e al. (2004) p oposed an in e ne -based p ojec managemen con ol sys em using pe o mance indica o s ( o people, cos , ime, quali y, sa e y, en i onmen , clien sa is ac ion, and communica ion) ha achie e a be e moni o ing o he p ojec and e en benchma king. Pe e a and Im iyas (2004) in oduced a ime and cos in o ma ion sys em o p ojec managemen , in eg a ing MS AccessTM and MS P ojec TM, which is specially sui ed o SMEs in he cons uc ion sec o . Al-Reshaid e al. (2005) de eloped and implemen ed a web-based p ojec con ol sys em o p econs uc ion s ages: easibili y, design, and ende ing. Finally, Li e al. (2006) designed a eal- ime in e ne -based p ojec managemen sys em ha gene a es cons uc ion p og ess epo s using he ea ned- alue me hod. Kim and Liu (2007) ook one s ep u he . They a emp ed o sol e he issue o in eg a ing cos da a om mul iple p ojec s in o co po a e managemen ; hus, a cos objec was designed as he basic elemen o he model in o de o p ocess da a and e ie e in o ma ion. Likewise, Benjao an (2008) de ised a cos con ol sys em o cons uc ion p ojec s, sui ed o SMEs, and based on he ea ned- alue concep . Kanoglu and A di i (2001) success ully deal wi h he p oblem o in eg a ing p ojec managemen and business managemen unc ions using a holis ic app oach. These au ho s de eloped a compu e -based in o ma ion sys em, called ASAP, o manage he in o ma ion low among pa icipan s in CEA i ms. This sys em makes use o MS P ojec TM o planning pu poses a he p ojec le el. I also includes ex e nal da abases o s anda ds, speci ica ions, codes, and egula ions. ASAP is no only ocused on indi idual p ojec s bu also on he business as a whole. Shi and Halpin (2003) encou aged he use o in eg a ed managemen sys ems adap ed o he unique cha ac e is ics o he cons uc ion indus y, as dis inc om he manu ac u ing sec o . They also enume a ed he basic ea u es ha should be equi ed o an ERP sys em implemen ed in a cons uc ion company: p ojec o ien ed, in eg a ed, pa alleled and dis ibu ed, open and expandable, scalable, emo ely accessible, and anspa en , as well as eliable and obus . O he au ho s only handle some pa o he global challenge, which is none o he han in o ma ion exchange using web-based echnology (Chan and Leung 2004; Zhiliang e al. 2004). As a las con ibu ion, Fo cada e al. (2007) de eloped a web-based sys em o documen a ion managemen speci ically applied o [ 8 ]Re is a de la Cons ucción Volumen 8 No 2 - 2009 páginas: 4 - 17 Pellice E. - Pellice T. M. - Ca alá J. ] SMEs in he cons uc ion indus y; his sys em allows in e ne exchange o documen a ion among di e en s akeholde s o he p ojec wi h app op ia e egis a ion and access con ols. All hese con ibu ions, om bo h p ojec and business app oaches, conside ed a ela ional da abase as he co e o he sys em. This kind o da abase managemen sys em (DBMS) is highly sui able o building cus omized managemen sys ems a ound i (Da e 2000; Benjao an 2008). Managemen sys em Business o ganiza ion Ou a ge o ganiza ion is a p ojec -based company wo king in he cons uc ion indus y, ei he a con ac o o a CEA company. Fo his kind o en e p ise, business managemen p esen s addi ional di icul ies ha can be summa ized as ollows (Gann and Sal e 2000; Shi and Halpin 2003; Pellice 2005): 1. S a egic (long- e m) planning: o ecas ing u u e con ac s is a complex ask; hus, a good p ocu emen s a egy is essen ial o he su i al o he business. 2. Ope a i e (sho - e m) planning: p ojec s a e subjec ed o delays o changes in speci ica ions ini ia ed by clien s o hi d pa ies; hus, an in e nal eo ganiza ion is needed o ealloca e esou ces. 3. O ganiza ion: in eg a ion o each membe o he p ojec eam wi hin he company’s hie a chy, and he inc easing numbe o subcon ac o s in ol ed may lead o complex s uc u es. 4. Coo dina ion: pe sonnel mus be kep well mo i a ed and adequa ely lead. 5. Con ol: delays o changes in sho - e m planning mus be moni o ed closely o de ec de ia ions so ha co ec i e ac ions can be aken as needed. A ypical business model is ou lined in Figu e 1, and is based on an open sys ems app oach in which he company in e ac s wi h he ex e nal en i onmen . Each p ojec o igina es in a bid p epa ed by he company o ul ill a eques om a clien . A signed con ac be ween a company and a clien ollows, al hough his con ac may be a e bal one. The aim o he con ac can be any wo k ha a company can pe o m du ing he cons uc ion p ocess: easibili y s udies, design documen s, buil in as uc u es, main enance wo ks, e c. The p oduc ion o he company is un by p ojec s. Resou ces a e needed o deli e he end p oduc . They may be in e nal (human esou ces, equipmen and in as uc u e) o ex e nal (supplies and subcon ac ing o human esou ces and equipmen ). I is likely ha some o he company’s esou ces mus be anspo ed om he cen al o ice o he wo k si e in o de o ca y ou a cons uc ion p ojec . In addi ion, he i m is hie a chically o ganized, wi h well-de ined pe sonnel ca ego ies and wo k pos s. No only manpowe , echnicians and expe s a e needed, bu also adminis a i e pe sonnel. Mo eo e , e e y employee has one supe iso ha o e sees his/he wo k. The ac i i ies ha ake place in a cons uc ion i m (CEA o con ac o ) can be p oduc i e o adminis a i e. The o me a e p ojec -based, whe eas he la e a e business- ocused (Gann and Sal e 2003). Adminis a i e ac i i ies a e non-p oduc i e ac i i ies, ca ied ou mainly by adminis a i e pe sonnel ha canno be exclusi ely associa ed o a speci ic con ac ; consequen ly, hey a e calcula ed as o e head (Pellice 2005). Sys em a chi ec u e A DBMS p o ides he company wi h cen alized da a con ol. A DBMS has many ad an ages (Da e 2000): sha ing da a, educing edundancy, a oiding inconsis ency, suppo ing ansac ions, main aining in eg i y, and en o cing secu i y. The main p inciple unde lying a DBMS is ha each da um can only be inpu one ime. Two main kinds o da a a e conside ed: p ima y con igu a ion da a, in oduced by he sys em adminis a o , and ope a i e da a, en e ed by pe sonnel. The sys em a chi ec u e equi es addi ional elemen s ha a e a anged in h ee ie s (Figu e 2): p esen a ion ie (use in e aces and o ms), applica ion ie (que ies), and da a ie ( ela ional ables). Inpu da a a e in oduced h ough he i s ie (in e aces) and p ope ly s o ed in ables ( hi d ie ). In o ma ion is hen e ie ed om he i s ie ia epo s and pi o ables (in e aces) using da a s o ed in he hi d ie wi h he adequa e exploi a ion o da a (second ie ). Ou in eg a ed managemen con ol sys em, called COGEST, is de eloped using MS AccessTM as he DBMS. This so wa e ool is widely used, and i is also linked o he Mic oso O iceTM package. Subsequen upg ades o COGEST also un in MS SQL Se e TM. Besides, MS AccessTM and MS ExcelTM a e in eg a ed using ODBC (open da abase connec i i y) and Visual Basic o Applica ionsTM. S uc u ed Que y Language (SQL) is used o que ies. The sys em is based on clien /se e a chi ec u e. The se e is he DBMS i sel , and he clien s a e he applica ions ha un on op, bu on di e en compu e s. Thus, he i s and second ie s un on clien s and he páginas: 4 - 17 [ 9 Re is a de la Cons ucción Volumen 8 No 2 - 2009 [ Pellice E. - Pellice T. M. - Ca alá J. ] Figu e 1 Business o ganiza ion model se e holds he ela ional ables. Cu en ly, he sys em is main aining 143 ela ional ables, 170 que ies, 30 pi o ables, and 197 o ms. COGEST pe o ms in eal- ime. E e y employee wi h a p e-es ablished igh o access can exchange in o ma ion wi h he sys em ins an aneously. This a ibu e leads o ema kable ime sa ings. I is i al o ake quick decisions when p oblems a ise, and he e o e, COGEST allows o imely ac ions o be aken by e e y manage in he hie a chy. Se e al di e en in e aces a e designed o each pe sonnel ca ego y wi hin he company. The use s a e ca ego ized acco ding o hei unc ions, di e en ia ing ca ego ies by ype o company (con ac o o CEA i m). Common ca ego ies o bo h ypes o companies a e sys em adminis a o , chie execu i e o ice , head o depa men , adminis a i e pe sonnel, and ecep ion desk pe sonnel. The e a e h ee speci ic ca ego ies o cons uc ion companies: cons uc ion si e manage , ield enginee / o eman, and basic use ; while speci ic ca ego ies o CEA companies a e p ojec manage , p ojec enginee , and basic use . Table 1 summa izes he pe sonnel ca ego ies in a hie a chical s uc u e, which also indica es i he wo k pos is adminis a i e o p oduc i e ( o CEA company o con ac o ). Those use s ha can be conside ed in mo e han one ca ego y a e shadowed in Table 1. The access le el o he di e en sys em capabili ies and he secu i y s age acqui ed depend on he loca ion o he wo k pos wi hin he o ganiza ional hie a chy o he company, as well as he adminis a i e and manage ial speci ica ions. COGEST asks o he use ’s ID and passwo d when logging on o he sys em; howe e , i he compu e is se o a ce ain indi idual, hen i only asks o he passwo d. I he in ended use is accep ed, he use ’s pe sonal in e ace is displayed. The access le els can be upda ed by he sys em adminis a o i necessa y. Taking all his in o accoun , he basic scheme o da a low in he o ganiza ion is illus a ed in Figu e 3. I is based on ou logical s eps: da a inpu and alida ion, da a s o age and exploi a ion, ou pu o in o ma ion, and ac ion. E e y employee inpu s ime spen on di e en asks o he co esponding con ac ; expenses, such as es au an meals, anspo a ion, pa king, supplies, and he like, can also be cha ged. Employees wo king in ne wo k-equipped o ices inpu da a e e yday h ough he compu e sys em, whe eas employees wo king on- si e in oduce da a di ec ly h ough he in ane , o by means o pape o e-mail epo s deli e ed weekly o he adminis a i e s a . On a daily basis, adminis a i e pe sonnel inpu supplies, en ed equipmen , ou sou cing se ices and subcon ac ing o each con ac h ough he compu e Figu e 2 Concep ual sys em a chi ec u e [ 10 ]Re is a de la Cons ucción Volumen 8 No 2 - 2009 páginas: 4 - 17 Pellice E. - Pellice T. M. - Ca alá J. ] sys em. In oices a e also eco ded o he co esponding con ac s. Addi ionally, adminis a i e employees can also inpu ex e nal da a ( a ios, o example) o be a ailable o benchma king pu poses. In e nal supe iso s check he da a inpu by hei subo dina es, being p oduc i e o non-p oduc i e ac i i ies. This supe ision p ocedu e can be so ened o ha dened acco ding o wo k pos s, unc ions, asks, and con ac s, always depending on he co po a e policy. Wi h all necessa y da a in he ables o he DBMS, use ul in o ma ion can be gene a ed h ough que ies using SQL. This in o ma ion is aken ou by way o epo s and pi o ables. Repo s a e speci ically designed o ob ain ce ain in o ma ion ela ed no only o cos and ime (pe pe son, ask, con ac , depa men , o company), bu o bids and con ac s ( ega ding hei s a us, esou ces, budge , e c.) as well. Figu e 4 shows a ypical mon hly epo ega ding ime (inpu hou s, heo e ical hou s, o e ime, accumula ed deb ime om p e ious mon hs, and cu en hou s o be ecupe a ed by he employee), and subsis ence cos s (mileage, a el displacemen s, es au an meals, o he s ela ed o a el such as pa king, and supplies). Pi o ables use MS ExcelTM o ac i ely analyze he many a iables ha a ec he pe o mance o he company, such as he annual e olu ion o p oduc i i y and p o i abili y, o inancial a ios. They can also be used o compa e pas ac i i ies wi h he cu en s a us, o o o ecas u u e scena ios. This ea u e is ex emely impo an bo h o a oid po en ial p oblems, and o acili a e benchma king; ex e nal a ios can be inpu o he sys em and may be used o con as and o ob ain aluable conclusions. Concep ual da a model Acco ding o Da e (2000), a concep ual da a model is a heo e ical, logical de ini ion o he en i ies and ela ionships modeling he s uc u e o he da a. An en i y is any dis inguishable objec o be ep esen ed in he da abase, whe eas a ela ionship is a bidi ec ional link among en i ies. The en i ies e lec in o ma ion abou he company, in gene al, and each p ojec , in pa icula . The DBMS is concep ually modeled using ela ional ables. COGEST is comp ised o 50 en i ies, g ouped unde eigh headings (see Table 2): egula inpu s, pe sonnel, esou ces, con ac s, asks, in o ma ion, p ocu emen , and communica ions. The unique ela ionships among en i ies a e complex in na u e. A ull accoun o he in e wo king o hese ela ionships is beyond he scope o his pape ; howe e , ADMINISTRATIVE STAFF CEA COMPANY PERSONNEL CONTRACTOR PERSONNEL Sys em Adminis a o Chie Execu i e O ice Head o Depa men Adminis a i e Pe sonnel P ojec Manage Cons uc ion Si e Manage P ojec Enginee Field Enginee / Fo eman Recep ion Desk Pe sonnel Basic Use Table 1 Use ca ego ies by hie a chy Figu e 3 Basic scheme o da a low páginas: 4 - 17 [ 11 Re is a de la Cons ucción Volumen 8 No 2 - 2009 [ Pellice E. - Pellice T. M. - Ca alá J. ] he ollowing desc ip ion o he eigh g oupings should se e o illus a e he unc ionali y o he sys em. Fu he mo e, Figu e 5 illus a es hose ables linked o he p ocu emen g oup o en i ies and hei ela ionships as hey appea in he da abase (in Spanish language). The i s g oup, “Regula Inpu s”, is he co e o he model; i ecei es he ope a i e pe iodic da a (daily, weekly, o mon hly) ha eed he sys em, and makes hem a ailable o he o he en i ies ha depend on hese inpu da a: ime o pe sonnel, and money o supplies, en ed equipmen , subcon ac ing, and in oices. Analy ical, budge a y and gene al accoun ing a e ob ained om he inpu da a by using comme cial accoun ing so wa e ha is linked o he sys em. Figu e 6 displays he basic inpu in e ace in which each use en e s he ime spen and he subsis ence cos s o he di e en asks o he speci ic con ac s. The second g oup o en i ies, “Pe sonnel”, con ains a desc ip ion o each wo k pos and he indi idual ha occupies i . No only a e he cha ac e is ics o he wo k pos aken in o conside a ion, bu also he con ac ual condi ions o each indi idual wi hin he i m. The sys em keeps a con inuous eco d o any changes in condi ions (see Figu e 7). These da a allow he sys em o au oma ically calcula e he cos pe hou o any employee, aking in o accoun he company’s o e head. The heo e ical me hodology, he implemen a ion p ocedu e, and he calcula ions o uni a y cos s applied a e ho oughly explained in Pellice (2005). This me hodology, combined wi h he capabili ies o he sys em, enhances he managemen o he i m by limi ing o e head, imp o ing p oduc i i y, e ealing a eas o e iciencies and ine iciencies, and g adually adjus ing he en i e p ocess. As pa o he “Pe sonnel” g oup o en i ies, he o ganiza ional hie a chy de ines he s uc u e o he business: boa d o di ec o s, depa men s, p ojec s, uni s, e c. Each indi idual, h ough his/he wo k pos , has a place in he hie a chy o he company. Likewise, con ac s mus be assigned o he co esponding depa men and uni i he company wishes o ha e ull knowledge o how each is pe o ming. Figu e 4 Mon hly epo on pe sonnel o ime and subsis ence cos s G oups o En i ies En i ies Regula Inpu s (6) Dia y – Ca ego y – Concep – Daily Hou s – Documen – Da a Pe sonnel (7) Wo k Pos – O ganiza ional Hie a chy – Quali ica ion – Labo Ag eemen – Wages – Desc ip ion – Complemen a y Da a Resou ces (6) Vehicles – Equipmen – Ma e ials – Auxilia y Facili ies –Supplie s – Manpowe Ou sou cing Con ac s (10) Clien s – Join Ven u es – Budge s – Con ac ing – Sub Con ac ing – In oicing – Desc ip ion – Na u e – Codi ica ion – S a us Tasks (3) Ac i i ies – Sub Complemen a y – Sub Basic In o ma ion (3) Accoun s – Ex e nal Reco ds – Uni P ices Da aBase P ocu emen (10) Tende s – Bids – Type P ocu emen – Awa ded – Demand – Join Ven u es – Ex e nal Tende s Da a – Type Gua an ee – Type Paymen – Wa an y Communica ions (5) Le e – Fax – Minu es – Elec onic Mail – In e nal Mail Table 2 Concep ual g oups o en i ies [ 12 ]Re is a de la Cons ucción Volumen 8 No 2 - 2009 páginas: 4 - 17 Pellice E. - Pellice T. M. - Ca alá J. ] Figu e 5 Da abase ables o p ocu emen p ocess and hei p ima y ela ionships The “Resou ces” g oup includes all esou ces ha he company needs o ca y ou i s di e en p ojec s. Six en i ies a e conside ed: ehicles, equipmen , ma e ials, auxilia y acili ies, supplie s, and manpowe ou sou cing. The la e includes ex e nal p o essionals as well as expe s. Figu e 8 depic s he inpu da a equi ed by he sys em o an ex e nal company. The ou h g oup o en i ies is “Con ac s”, which na u ally includes any da a ele an o he con ac : desc ip ion, na u e, and s a us. Any gi en con ac mus be ela ed o a clien who pays o he wo k. I also akes in o conside a ion he in oicing phase, acco ding o con ac speci ica ions. I is di ec ly linked o he esou ces en i y, since di e en kinds o supplie s a e needed: ma e ials, ehicles, equipmen , o subcon ac ing. The “Budge s” en i y e lec s he budge a y da a ha will p o ide o sui able cos con ol; Figu e 9 illus a es he main o m o he con ac en i y. Finally, he possibili y o join en u es is con empla ed by he sys em. Figu e 6 Basic en y o he sys em o p oduc i e pe sonnel Figu e 7 Desc ip ion o employee and wo k pos