Combining a Quantitative Approach of Planning and Control with a Lean Approach: Reflections on a Case Study

A lean approach is idealizing and participative. Applying it to production planning and control has to be directed to the removal of inventory, to the application of “pullâ€, to a smooth flow and to a high participation of all people involved, through the use of standard tools. This seems to conflict with a quantitative approach of production planning and control. Such an approach starts with the acceptance of certain supply and manufacturing restrictions and is directed to properly dealing with these restrictions. The concept trade-off is very important in this approach. A key for a good co-existence of the two approaches may be the concept regularity. Flow is a form of regularity. It is not always possible to organize flow in all parts of the operation, but it is always possible (and necessary) to strive for regularity. And it is generally possible to realize a high degree of regularity. So, if regularity is stressed instead of flow, the two approaches may co-exist more comfortable. Cyclic schedules are an important form of regularity, especially in the semi-process industry. This paper reflects on a case study where the design and implementation of cyclic schedules in a semi-process plant is embedded in a company-wide lean improvement programme.