The MPS Rough-Cut Capacity planning function makes it possible for you to determine, at a high-level, how a given MPS plan could affect user-defined key resources.

You can define planning routings for end items, or use manufacturing bill of material and routing information to generate them automatically. MPS multiplies the planning routings by open firm and forecasted independent demand to determine the usage quantity (load) for each key resource, by week, and to identify over-capacity conditions (that is, where load exceeds capacity for a given week).

The plan is called "rough-cut" because it does not consider existing inventory or current manufacturing order, purchase order, or requisition status when calculating load. It looks only at open, independent demand — sales orders, forecasts, and issue reservations. The open quantity for each open independent demand requirement is multiplied by the per-unit quantity and added to the fixed usage quantity for each planning routing record linked to the demand record part. The lead time offset of the planning routing record is subtracted from the demand record's need date (using shop days if you selected Shop Days as the Lead Time Calculation method on the Configure Production Control Settings screen) to determine when the key resource is consumed. The usage quantities for each key resource are summarized by week and then compared to the capacity amount defined on the Manage Key Resources screen.

The Create/Update Rough-Cut Capacity Plan process also produces a report showing key resource load and capacity by week. You can run the report to show only key resources and weeks where load is over a certain percentage of capacity.

This function also generates an Overcapacity MPS action message for every weekly period where a key resource's load exceeds its capacity. These Overcapacity action messages are visible on the Manage Master Production Schedule Action Messages screen and the Print Master Production Schedule Action Message Report.