29, March 2018
Production Planning and Scheduling Challenges and Improvement Opportunities
The two extreme end of production systems are low-mix/high-volume production and High-mix/low-volume. When compared to low-volume, scheduling in high-volume is relatively simple - establishing a sufficient rate of output to meet forecasts. On the other hand scheduling in low-volume tend to be complex and concerned with trade-off between inventory, capacity, and customer service.
Recognizing the fact that many manufacturers in the United States operate in high-mix/low-volume environments, it is important that measures are put in place to proactively address the many challenges they face which includes, but are not limited to, production planning and scheduling. This low-volume scheduling complexity which is characteristic of many job shops is exaggerated by factors such as bottleneck continuously moving, balancing ever changing demand with available capacity, long job waiting and throughput time, high work-in-process, variable travel paths, and many instructions because of change in jobs, etc.
In general, effective production planning and scheduling is a process that covers a wide variety of activities to ensure that materials, equipment and human resources are available when and where they are needed. Improving this process follows the standard practice of first studying and mapping the process, capturing both the flow of information and materials. The mapping needs to include upstream processes such as demand management (sales, marketing, forecasting) and downstream processes where the actual production and warehousing takes place. In many cases such mapping results in recognition of a number of wastes resulting from inadequate or poor communication. Facilitating effective communication among different processes on the value stream is one major step toward improving production planning.
Production systems, especially job shops, are a challenging environment and requires the recognition of the need for multi-point initiatives to help with improving their processes. The “lean” approach and “building blocks” is one avenue providing the tools and methodologies in support of such initiatives.
In a separate blog I have addressed the lean building blocks and tools and their importance to improving processes. Workplace organization, plant layout and cell design, setup reduction, use of visuals for enhanced communication, total productive maintenance, standardized work, value stream mapping, and managing flow (including Theory of Constraints, Pull/Kanban, and load leveling) are some of the tools and methodologies that are covered under the umbrella of lean building blocks. Integration of such tools and methodologies is another step toward improving how we can deal with some of the complexities of High-mix/low-volume job shop production environments. The ultimate goal is to gain some of the advantages of high volume production environments which include utilizing sequential processing, simple routings, predictable processes, effective information flow, and flexibility.