Transient Analysis and Scheduling of Bernoulli Serial Lines With Multi-Type Products and Finite Buffers

Serial lines with multi-type products, finite buffers, and stochastic machine breakdowns are commonly seen in flexible production systems, where multiple small-size production batches with various part types are performed according to the customer orders. Such production systems rarely reach their steady states. Therefore, analyzing the transient behavior of these systems has an important research significance, especially for real-time operations and management. In this paper, we analyze the performance of the multi-type serial line under a given production schedule. Mathematical models and analytical solutions are developed for one- and two-machine lines. For longer lines, an efficient aggregation method is proposed to approximate the performance measures with high accuracy. In addition, based on performance analysis, the optimal scheduling of batches is discussed. Numerical experiments show that our proposed analysis method can be successfully applied to production scheduling problems. Note to Practitioners - Flexible serial lines with multi-type products are widely seen in practice, e.g., in automobile paint shops for vehicles with multiple types, and furniture assembly plants with various styles. In order to optimize such systems, achieving a real-time transient performance measure with high accuracy is of great importance. In this paper, mathematical models, as well as analytical solutions, are developed for transient performance analysis. A computationally efficient method is proposed to approximate the transient performance for longer lines. In addition, scheduling algorithms to lower the maximum batch completion time and total flow time are also discussed. These analysis methods and scheduling strategies can guide the operators and managers to improve production efficiency.