Dynamic scheduling of design activities with resource constraints

A design process can be represented as a network of design activities. A number of design projects may be undertaken simultaneously. This paper deals with the problem of scheduling design activities of multiple design projects competing for the limited available resources. The problem of determining a schedule subject to precedence and resource constraints is difficult to solve. It becomes even more complex when unforeseen changes are considered, for example, in the level of resources. Therefore, the scheduling problem is decomposed into a series of multidimensional (multiresource) knapsack problems. Due to high computational complexity of the multidimensional knapsack problem, two solution procedures are proposed     

Resource constrained scheduling of hierarchically structured designactivity networks

In this paper, a new approach to the problem of scheduling of design activities with precedence and multiple resource constraints is proposed. In addition to the AND type relationship, OR and EXCLUSIVE OR relationships may also exist between design activities. In order to handle these logical relationships, IDEF3 is used for network representation. A large network of design activities can be arranged in different levels of abstraction. A procedure is proposed to transform an IDEF3 model into a set of alternative precedence networks. In the networks selected, the activities that are resource independent are grouped with a partitioning procedure. In order to increase the efficiency of the search for the best schedule, a procedure based on the Christofides et al. (1987) reduction procedure is introduced to determine a lower bound on the completion time of the hierarchically structured design activity network