Comparing Planning Modes

Planning mode	Description
MRP	Plans requirements in order by the lowest level in which each item appears in any bill of material (that is, all end items first, then all items at the next level, and so on). The item's Low Level Code determines when MRP plans requirements for it. MRP plans each requirement from the current date, backward in time to the item's lead time, batching together similar requirements. MRP does not consider routings, resource capacity, or shifts. It generates planned orders and exception messages. The Get ATP/CTP buttons are disabled.
APS	Plans all requirements for one demand before planning the next demand, based on order priorities and due dates. It considers whether resources (crew, machines, and fixtures) are on-shift and not busy working on other demands. Resources can work on only one task at a time. That is, if drillpress_ABC is working on Operation 10 of Job 123 at 10:00 a.m., drillpress_ABC cannot also work on Operation 10 of Job 456 at 10:00 a.m. APS generates planned orders and exception messages, and reports detailed resource usage. On forms such as Customer Order Lines and Job Orders, the Get ATP/CTP buttons are labeled Get CTP.
Infinite APS	This mode is selected by default when you install SyteLine. Plans all requirements for one demand before planning the next demand, based on order priorities and due dates. However, unlike APS planning, it assumes your resources (crew, machines, and fixtures) can work on an unlimited number of tasks while in a working shift period. The system limits a resource's production only by the available on-shift time. Infinite APS generates planned orders and exception messages, and reports detailed resource usage. The Get ATP/CTP buttons are labeled Get ATP.

Of the three planning modes, the APS mode is the most realistic view of your facility; the system does not over-promise an order during a period when there are actually no available resources to complete the order.

The APS services and planner database must be running on your SyteLine servers in order for APS and Infinite APS modes to function correctly. For instructions on starting the Planning and Scheduling Gateway and Server services on the utility server and for starting the planner database on the planning server, see the Installation Guide.