| The purpose of this research was to design a closed-loop process control system for a pull-type manufacturing scheme. It will meet the required daily quota and minimize shipping and work-in-process inventory while accounting for high levels of absenteeism and turnover that directly effect work station yield distributions. The closed-loop production scheme, referred to as the Adaptive Just-In-Time Production System (AJITPS), circumvents low and variable yield rates by dynamically feeding back production information in order to adjust the number of parts that should be included in a production container. This was accomplished algorithmically via a Kalman Filter that predicts the amount of pieces the first workstation must place in a production tote in order to meet the target production quota. The advantages of a JIT pull-type production system includes the minimization of work-in-process inventory, the reduction of raw material inventory, and leaner and more flexible production. In general, all JIT literature and "how-to" manuals assume a high and stable quality level in order to meet the target output quota. The basic premise of the AJITPS is to successfully implement a pull-type production scheme with its associated benefits even though the JIT quality implementation criteria is not met. The closed-loop algorithm allowed a pull-type production line under non-ideal JIT quality implementation criteria to effectively meet a production quota with a minimum work-in-process and shipping inventory accumulation. The key to the Kalman Filter algorithm is the weighting function, which statistically dampens the effects of going beyond or below the target production quota. |
