To perform a project material requirement planning (project MRP) calculation, you must have entered parts with on-hand quantities and structures. Also, some forms of supply and/or demand such as customer orders, shop orders, and purchase orders must be associated with these parts. Beyond these basic requirements, many other factors affect project MRP. You should be aware of them before performing a project MRP calculation. These factors are listed below.
Control parameters determine the conditions for running project MRP:
The planning of project MRP start times depends on the information entered in the project calendar. Only work days can appear in the calendar. Weekends and holidays are not counted when setting the start time for project MRP.
The selections that you make in the Manufacturing tab of the Site window determine how the system processes the part during project MRP. Selecting the Use Rel Purch Reqs in Planning check box causes project MRP to not delete purchase requisitions in the Released status at the start of the project MRP run. These are viewed as supply later in the project MRP process.
You can specify the lead time and the lead time code for each inventory part on the Acquisition tab of the Inventory Part window. This information controls how the part is processed when it is in demand. The lead time code determines whether the system creates a manufacturing or purchasing proposal to fulfill the demand for the part. The default supply type on the Planning Data tab of the Inventory Part window determines the type of proposal: requisition, order, or schedule.
The information that you enter on the Planning Data tab of the Inventory Part window determines how the system processes the part during project MRP. The planning method and lot size values determine how the demand is processed. During project MRP, the system does not process parts with a planning method B (Order Point Planning), C (Replenishment Level), or N (Next Level Demand). The value in the Proposal Release field determines whether the system creates order proposals or any type of supply, such as shop requisitions, and purchase requisitions. When generating proposals, the manufactured/acquired split percentages defined on the Planning Data tab are considered when you generate proposals for both in-house and outside sources to obtain the supply details.
Before starting project MRP, you must enter the structures of the parts that will be manufactured. These structures must have a structure type of Manufactured, (standard manufacturing). Also, they must be valid at the time of manufacturing. project MRP breaks the structures down into components for the calculated start date. Note that project MRP works with structures for both standard parts and project specific parts, which does not have a variant or serial number.