A generic construction process modelling method

A variety of modelling methods has been used to model construction processes and projects, either during normal project planning or for process re-engineering efforts or research. One common method, which is widely used by construction industry practitioners, is scheduling. In addition to schedules, some companies have used a simple box-and-arrow method, which graphically resembles schedules, for analysing their working processes. More formal methods such as IDEF0 havebeen used in re-engineering projects and by researchers. All these methods are limited in scope and cannot be used to model all the aspects of the processes that practitioners are interested in. A new generic construction process modelling method, GEPM, was developed to overcome the deficiencies of the current methods. GEPM uses object-oriented principles, and has borrowed features, such as activity, task, and temporal dependency, from methods like IDEF0 and scheduling. GEPM is flexible in the sense that the conceptual model can be changed to achieve additional special features. This capability is also supported by the database implementation, which enables users to interact with the developed process models through views that represent partial models. The views support the IDEF0, scheduling, and simple flow methods. There are, though, rules for how to convert between the partial models through views. The evaluation of GEPM showed that more modelling features, i.e. modelling power, are obtained in comparison with the earlier methods. One of the essential features of GEPM is the distinction between activities and tasks. Activities define how an action will be carried out, generally using predetermined inputs to achieve a predetermined output, whereas tasks are activities with additionally specified starting and finishing times, duration and location. Moreover, a task has a type-attribute that refers to an activity where its overall template is defined. Before the actual evaluation, case material from a real project was preliminarily tested with GEPM along with the prototype application. It turned out that some additions were needed to the conceptual model of GEPM and to the prototype application. GEPM can be used for process improvement, process management, and for enhancing communication in a construction process. One usage scenario for GEPM is to define quality systems and reference models, using the activity sub-model and storing the results in the GEPM database. A project-specific model can be derived from the reference model using conversion rules, and it eventually turns into a project specific-schedule with tasks.