A plan structure identifies the different subfamilies of parts that are grouped under a top-level parent Level 0 master-scheduled part. A plan structure is a generic definition used to facilitate two-level master scheduling.
IFS/Master Scheduling (MS) uses plan structures to disaggregate family forecasts down to individual Level 1 master-scheduled parts. It is also used to aggregate data for Level 1 parts back up to the Level 0 family to which they belong.
Plan structures are divided into three elements: the structure header, the structure status, and the structure line items.
A structure header is where the part, site, and revision are identified. A plan structure can be of the Manufacturing structure type.
A plan structure may have several structure header revisions. A structure header is automatically created when a new part revision is created for an inventory part of the Manufactured part type of which the planning method is set to O in the Inventory Part/Planning Data tab.
The status of the structure indicates how the structure information can be used. Possible statuses are:
| Status | Description |
| Tentative | A structure is created in the Tentative status and normally, this is the default value. This status indicates that the structure is not yet usable, and the structure data will not be used by planning. components may be changed in this status. |
| Plannable | A structure promoted to the Plannable status can be used to calculate cost and planning information. Components may be changed in this status. |
| Canceled | The structure has been canceled and will not be available for use in planning nor used to generate costing information. You can change to this status at any time. |
Structure line items are the components of the plan structure. Each line item identifies either a subfamily (parts with planning method T) or a Level 1 master-scheduled part as well as the quantity per assembly. The Quantity per Assembly field should typically hold a value between 0 and 1. This indicates the percentage that the subfamily or part constitutes of the parent family.
The quantity per assemblies for all subfamilies or Level 1 parts of a parent family should typically total up to be exactly 1. When the total exceeds 1, a warning message is displayed to users, who can still commit the data to the database. This total will exceed 1 when users typically want to overplan a subfamily or part. Another restriction is that a subfamily or Level 1 part can belong to one and only one plan structure (or top-level family).