A Performance Management Tool

In many ways the most interesting to management of the param­eters examined here, the cumulative lead time represents the total time required to produce and make available a product from its starting or raw materials, perhaps through many manufacturing levels.

The conventional back-scheduling process, using level-by-level lead times to build up a cumulative lead time (e.g. in a product lead time display), operates on the assumption of no delays between levels—no stock, in other words. It represents a probably unachievable minimum lead time using then-current standards.

The lot traceability system provides, either as a printed report or as an on-line enquiry, full multi-level lot tracing. This is accom­panied by full transaction detail, as before. A full reverse lot traceability report or enquiry (lot source report) will then reveal dates and times for all relevant events between the receipt of the first lot of starting material or the first issue transaction at the lowest manufacturing level and the final approval of the highest level lot. This will provide actual cumulative lead time figures and lead times for all intermediate levels as contributors to the total. Comparisons can then be made with the theoretical cumu­lative lead time to show what excessive delays have occurred, management will have a clear view of true lead times, and a pattern of lead times can be built up over a period to act as a basis for real-world planning figures.

Manufacturing orders may be produced and received in a number of separate quantities. This pattern may have a significant effect on product availability in relation to capacity usage and material consumption. The lot traceability system records will reveal the pattern in detail, provided receipt recording is carried out rigor­ously according to each successive movement quantity.

Pharmaceutical and fine chemical production is often planned in campaigns, which are end-to-end sequences of manufacturing orders designed to avoid lengthy and expensive changeovers [2]. These are inherently in contravention of JIT principles [4].

These end-to-end sequences give rise to, or should give rise to, multiple product lots. Provided that there is some feature of the lot numbering system that will permit lots to be tied to their parent campaign as well as to their parent manufacturing orders, the data available in the lot traceability system can be used to trace the start and finish times and dates of the campaign as well as of every order and lot within it, and to plot the productive and non-pro­ductive times. Management may be able to use this data in efforts to reduce campaign sizes (the pharmaceutical equivalent of reduc­ing lot or batch sizes).

To be Continued

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