Item structures

Bill of Material (tibom1110m000)

For production planning, Enterprise Planning and Job Shop Control make use of the item structure and the routing for these items. The item structure, also called the Bill of Materials (BOM), describes the relationships between items in a production environment. Items that are related to each other have a parent-child relation:

Each parent-child relation has specific characteristics that are defined on the BOM line, such as scrap percentage, scrap quantity, and net quantity.

Enterprise Planning uses the bill of material for several purposes:

  • Material explosion for order planning
  • BOM generation for customized items (customized item derived from a standard item) (Make to Order (MTO).
  • The BOM is the basis for the Bill of Critical Materials (BCM) generation. Enterprise Planning uses the BCM for material explosion for master planning and for available to promise (ATP) checks across the whole planning horizon.

Item - Routings (tirou1101m000)

An item can have a routing and a routing can have one or more routing operations. Each operation describes a process step on a specific work center.

The operation defines the processing and waiting times and things such as scrap and yield. Enterprise Planning uses the routing to perform the following:

  • Generate the operations of the planned production orders. All operations together determine the planned start and finish date of the order.
  • Generate the project routing.
  • As the basis for the Bill of Critical Capacities (BCC). The BCC is used for master planning and Capable to Promise (CTP) checks of the resources. BCC is also used for CTP checking in the order planning horizon.

In the example above item A has a routing with 3 operations.

Operation 10 is the first operation and 30 the last operation.

Item C has two operations.

Note: 

The materials are always planned at the beginning of the routing except when on the BOM line it is defined that the material should be available at a specific routing operation (like C) that is linked to operation 20.

This link is defined on the Operation field of the BOM line.

When the Operation field is empty, the material is planned at the start of the routing which is at the start of operation 10.

BOM Line - Material-Routing Relationships (tibom0140m000)

The material-routing relationship is an extension of the Operation-on-BOM-line concept. The link between material and operation is dependent on the selection of the (quantity dependent) routing.

The screen dump below shows the material-routing relationship for a BOM line. The header defines the item and position of the BOM line in the BOM. Each line (record) defines a relation of this BOM-line item (component) to an operation for each specific routing.

With this relationship, you can link BOM lines to an operation of a specified routing.