Constralnt-based planning with integrated production scheduler over internet

Identifying and removing constraints from bottleneck activities help to reduce uncertainties in construction processes and increases the transparency of project management. The present means of look-ahead planning do poorly in resolving hidden constraints in the supply chain and information flow. Accordingly, work plans are vulnerable to the uncertainties that result in flow variation. It has been realized that reducing and eliminating critical constraints through better means of look-ahead planning are the keys to achieving reliable workflow and, consequently, increased productivity. This paper presents a constraint-based planning tool, Integrated Production Scheduler (IPS), to enhance planning reliability while adopting lean construction principles and the theory of constraints. Unlike the critical path method, the IPS models two additional types of constraints related to resource supply and information exchange. It employs four activity buffers: working, shielding, pulling, and screening for managing critical constraints and shielding the production from uncertainties. The implementation of the IPS is prototyped as a distributed scheduling system using Internet technologies such as Java and XML. It facilitates setting up a transparent project management environment where faster communication and active collaboration among project members are achievable.