A model for determining job throughput times for manufacturing flow line workcells with finite buffers

A model is presented for calculating the starting and finishing times of jobs processed in a group technology (GT)-structured flow line workcell in light of transient and steady state conditions. The GT-based workcell is becoming an important component of a just-in-time (JIT) strategy to gain increased productivity and proper response to customers in small-to-medium lot size manufacturing operations. Considering the four factors of machines in series, finite buffers between machines, piece-by-piece continuous flow processing, and setup times treated separately from processing times, the model provides critical information in implementing JIT such as job starting and finishing times as well as the makespan for processing a set of jobs. The recursive procedure of the model is presented in a step-by-step fashion, and illustrated through a numerical example. Furthermore, the performance of the model is evaluated through a set of industrial data by comparing results obtained from a deterministic simulation model.