To compute phase numbers for master-based planning

LN bases the phase number for master planning on the following data:

LN computes phase numbers for

Plan units (and the plan items that belong to it)
Plan items that are not part of any plan unit

In the master-planning process, an item that is not part of any plan unit is treated as a plan unit of its own.

Criteria for phase numbers

The phase numbers of the plan units must conform to the following criteria:

If two plan items are in different plan units, and one of these plan items is defined as a component of the other in a BCM, the phase number of the component's plan unit must be greater than the phase number of the parent's plan unit.
If a supplying relationship exists between two plan items that belong to the same site, the phase number of the supplying item's plan unit must be greater than the phase number of the receiving item's plan unit.
If a supplying relationship exists between two plan items that belong to different sites, and both items are controlled by central multisite planning, the phase number of the supplying item's plan unit must be greater than the phase number of the receiving item's plan unit.

Note

An item is controlled by central multisite planning if the Central Multi Site Planning check box in the Items - Planning (cprpd1100m000) session has been selected. Moreover, there must be a central multisite scenario that includes the sites involved. If you use the Compute Phase Numbers (cprpd6200m000) session to recompute phase numbers for central multisite planning, you need to specify the multisite scenario involved.

Similar criteria apply to plan items without plan units except LN uses the phase number of the plan item instead of the phase number of the plan item's plan unit.

Computation procedure

The computation of the phase numbers is an iterative process. You can choose between two methods:

Regenerative computation
Net-change computation

In a regenerative computation, every plan unit and every plan item without a plan unit initially gets phase number 0. LN then checks the plan units and plan items without a plan unit one by one and adjusts their phase numbers until the criteria for phase numbers are fully met. For information on the net-change computation, see Net-change phase number computation.

Example

Consider the following bill of critical materials with seven items:

Items A_1 belongs to plan unit 1, B_2 belongs to plan unit 2, and so on.

The computation yields the following result:

Plan item	Plan unit	Phase number
A_1	1	0
B_2	2	1
C_4	4	2
D_4	4	2
E_4	4	2
F_3	3	3
G_3	3	3

You can see the result of the computation in the Master Phase Number field in the Plan Unit (cprpd6100m000) session for plan units and in the Master Phase Number field in the Items - Planning (cprpd1100m000) session for plan items without plan unit.

Note

The phase number computation also checks for cycles in the bills of critical materials.