A robust approach to production scheduling incorporates downtime Issues and occurrences.
Production downtime can usually be attributed to one of three areas:
- Unplanned Downtime — this is when something goes awry. Could be a mechanical breakage or stoppage of any kind or an electronic problem.
- Planned Downtime – Production Related. For example, product changeover for molds, dies, etc.
- Planned Downtime – Maintenance Related.
The question is, how should we accommodate these issues into a production scheduling system? There are several options depending on what level of detail provides the most benefit.
At one end, for unplanned downtime, should we track those occurrences and attribute a reason code for analysis on trying to improve? Should we be able to dynamically adjust the capacity during that time and possibly reschedule and re-balance the production schedule based on those events? Usually, there is a threshold at which the feedback, reporting, analysis, and so forth would deem it vital. At the other end, if unplanned downtime is a minor inconvenience, then it might be most efficient just to build in a little buffer for such repairs into initial capacity considerations and let it go.
Planned Downtime – Production Related
As far as planned downtime that is production related, we need to examine what is the most efficient method to minimize this. Can we group different jobs or production runs together somehow, automatically, to minimize change overs? Are there special skill sets for technicians, that perform these change overs, that need to be considered? For example, if there is only one senior tech who can change dies on 40 ton presses, we do NOT want a production scheduling approach that ends up needing multiple press change overs at the same time. This is a question of managing more than one constraint, both the press and the technician.
Planned Downtime – Maintenance Related
Finally, for the planned downtime that is maintenance related, we have more choices. Do we adjust available capacity for those machines to reflect planned maintenance, for example, every 4 weeks, at 8 AM, for 2 hours? Or, would it be smart to schedule the planned maintenance as mini jobs, giving them the highest priority, so they are factored into the production scheduling and print out on workcenter reports? This decision will be based on whether is already a formal maintenance system in place or not.
Production Scheduling Incorporating Downtime
Production Downtime Tracking Calculation and Report with Resource Manager-DB