DECISION ANALYSIS WITH WITNESS SIMULATION: product development process modeling

Decision_anlysis with WITNESS.pdf

This paper presents a decision analysis technique on the results obtained from product development process model simulation. The design process involved in the industry is used as a sample application. The software used for simulation is called WITNESS. The simulation model uses the design structure matrix to capture the information flow between tasks where the tasks could be sequential, parallel and overlapped. The input data is fed to the model from an Excel spread sheet to facilitate easy experimentation by changing input data. Suitable probability distributions are used to model the task time, task cost and rework occurrences. The model computes the overall probability distribution of lead time and cost by assuming unconstrained resource availability. The results from simulation are used to assess the trade-offs involved between lead time and cost. The overall utility function of the proposed model is estimated using decision analysis techniques. Such a simulation model could be used for better project planning by identifying the bottleneck task and perform easy “what-ifs” by changing any input data. The model is extended by including the resource constraints assuming fixed labor.