Plan Materials at Operation Start, Planning Parameters

Plan Materials at Operation Start

This field applies to MRP and APS.

When the system is planning released jobs and production schedule releases, this field controls whether the materials for a job or production schedule release are required to be available at the operation's start date or at the job/PS release start date.

Select this field to plan the materials to be due at the start of the operation in which the materials are used. This method of planning results in a just-in-time material plan. In most cases (especially if you are using APS), you should select this field.

Clear this field to plan the materials to be due at the start of the job/production schedule. Typically, you should clear this field only if these conditions are true:

you want to have all materials ready before you release the job or PS release

all of the materials are not specified on the first operation in the routing.

NOTES:

Planned production schedule releases are only affected by this parameter if the planning parameter, Plan Planned Production Schedules, is selected.
This field also determines how requirements are displayed on the Time Phased Inventory Status form and on the Purchase Requirements Report.

MRP Processing

When MRP generates a PLN to satisfy a demand, it always plans the materials to be due at the start of the job. For jobs and production schedule releases, MRP considers the Plan Materials at Operation Start field when the following conditions are true:

The table below summarizes the other factors that determine how MRP plans the due date of materials:

Plan Materials at Operation Start NOT Selected
Job Scheduled AND Use Scheduled Times in Planning selected?	Job Start Date	Materials are due at
No	Not blank	Job's Start date
No	Blank	Job's End date - Fixed Lead Time + (Variable Lead Time * Qty)
Yes	n/a	Job's internal projected start date (calculated by the Scheduler--not displayed elsewhere)

Plan Materials at Operation Start NOT Selected

Job Scheduled AND Use Scheduled Times in Planning selected?

Job Start Date

Materials are due at

Not blank

Job's Start date

Blank

Job's End date - Fixed Lead Time + (Variable Lead Time * Qty)

Yes

n/a

Job's internal projected start date (calculated by the Scheduler--not displayed elsewhere)

Plan Materials at Operation Start Selected
Job Scheduled AND Use Scheduled Times in Planning selected?	Operation Start Date	Job Start Date	Materials are due at
Yes	Not blank	n/a	Operation Start Date
Yes	Blank	n/a	Job's internal projected start date (calculated by the Scheduler--not displayed elsewhere)
No	n/a	Not blank	Job Start Date
No	n/a	Blank	Job's End date - Fixed Lead Time + (Variable Lead Time * Qty)

Plan Materials at Operation Start Selected

Job Scheduled AND Use Scheduled Times in Planning selected?

Operation Start Date

Job Start Date

Materials are due at

Yes

Not blank

n/a

Operation Start Date

Yes

Blank

n/a

Job's internal projected start date (calculated by the Scheduler--not displayed elsewhere)

n/a

Not blank

Job Start Date

n/a

Blank

Job's End date - Fixed Lead Time + (Variable Lead Time * Qty)

APS Processing

If the job or production schedule is released but NOT scheduled, APS plans the materials based on the setting of the Plan Materials at Operation Start field.

NOTES: These notes apply if you are using APS.

If this parameter is cleared, the material demands will be due earlier than they were due in previous runs of APS Planning, before the job/production schedule was released. If you are running in APS mode, this situation may cause problems with resource capacity. Select this parameter to avoid this issue.
Items for which the the MRP Item is selected are not affected by this parameter; they always require materials at the job/PS release start date.
Planned orders (PLNs) are not affected by this parameter; required materials for a planned order are always planned at the start of the operation.
Firm jobs are only affected by this parameter if the planning parameter Preserve Pre-Released Production Dates is selected. If Preserve Pre-Released Production Dates is cleared, the materials are planned at the start of the operation.