A variety of modelling methods has been used to modelconstruction processes and projects, either during normalproject planning or for process re-engineering efforts orresearch. One common method, which is widely used byconstruction industry practitioners, is scheduling. In additionto schedules, some companies have used a simple box-and-arrowmethod, which graphically resembles schedules, for analysingtheir working processes. More formal methods such as IDEF0 havebeen used in re-engineering projects and by researchers. Allthese methods are limited in scope and cannot be used to modelall the aspects of the processes that practitioners areinterested in.
A new generic construction process modelling method, GEPM,was developed to overcome the deficiencies of the currentmethods. GEPM uses object-oriented principles, and has borrowedfeatures, such as activity, task, and temporal dependency, frommethods like IDEF0 and scheduling. GEPM is flexible in thesense that the conceptual model can be changed to achieveadditional special features. This capability is also supportedby the database implementation, which enables users to interactwith the developed process models through views that representpartial models. The views support the IDEF0, scheduling, andsimple flow methods. There are, though, rules for how toconvert between the partial models through views.
The evaluation of GEPM showed that more modelling features,i.e. modelling power, are obtained in comparison with theearlier methods. One of the essential features of GEPM is thedistinction between activities and tasks. Activities define howan action will be carried out, generally using predeterminedinputs to achieve a predetermined output, whereas tasks areactivities with additionally specified starting and finishingtimes, duration and location. Moreover, a task has atype-attribute that refers to an activity where its overalltemplate is defined.
Before the actual evaluation, case material from a realproject was preliminarily tested with GEPM along with theprototype application. It turned out that some additions wereneeded to the conceptual model of GEPM and to the prototypeapplication.
GEPM can be used for process improvement, processmanagement, and for enhancing communication in a constructionprocess. One usage scenario for GEPM is to define qualitysystems and reference models, using the activity sub-model andstoring the results in the GEPM database. A project-specificmodel can be derived from the reference model using conversionrules, and it eventually turns into a project specific-schedulewith tasks.
Keywords:process, modelling, generic, method, model,database, view
Institutionen för fastigheter och byggande , 2001. , 62 p.