Research communications: A simulation model of the “contract change” process Available to Purchase

Presents a simulation model of the “Contract change process” for an aerospace manufacturing firm. The model was developed to simulate the activities from the time when a customer’s request is received to the two points in time where a preliminary schedule and a formal proposal is returned to the customer. The model was developed in a two‐stage approach. First, the process was studied and documented in US Air Force integrated computer aided manufacturing definition language for function modeling an IDEF₀ model which defined the relationships between each pair of activities. Second, using the structural information provided by the IDEFo model, a simulation model using simulation language for alternative modeling (SLAMII) was developed. Data were obtained from archival sources in the department’s database. The data were analyzed according to the quarter in which they were received. From this, arrival time data distributions were estimated for each of the four quarters to capture the seasonality element in the company’s business. Next, the data were separated into three levels of difficulty to define complex, routine and simple tasks. From this, three distributions of activity times were developed for each set of tasks. The results will allow for the study of reengineering and downsizing decisions for the contract change process in the aerospace industry, under conditions of seasonal and task complexity variations.