Grouping with Hierarchically Structured Grouping WBS Elements 

Use

You use this procedure if you would like to have several grouping criteria, that is, several grouping WBS elements, in a plant to group requirements.

The grouping WBS elements are hierarchically structured in this procedure.

Prerequisites

If you would like to group the WBS elements according to two criteria, for example, ordering parties from the public sector/ private sector, you create one grouping WBS element for each grouping criterion in the plant.

Features

In MRP, a material that is allowed to be planned with requirements grouping is planned:

Example

You can imagine the material requirements planning of a project in the form of a pyramid. At the top is the finished product that is planned with the individual WBS element.

The lower levels of the hierarchy represent the hierarchy of the grouping WBS elements. Every level simultaneously represents a BOM level. The lowest level represents the lowest BOM level with raw materials that are planned without reference to the grouping WBS elements as collective requirements and are managed in the plant stock.

The following illustration shows the hierarchical structure of grouping WBS elements in a plant. Every grouping WBS element has been created for a particular grouping criterion:

Grouping WBS Elements

The grouping WBS elements 1 to 6 correspond to the following grouping criteria:

WBS Elements

The following WBS elements have been created in different projects: WBS 1.1, WBS 1.2, WBS 2.1, WBS 2.2

Assignments Between WBS Elements and Grouping WBS Elements

You must maintain the following assignments between WBS elements and grouping WBS elements:

Grouping WBS el. 1

Grouping WBS el. 2

Grouping WBS el. 3

Grouping WBS el. 4

Grouping WBS el. 5

Grouping WBS el. 6

WBS 1.1

WBS 2.1

WBS 2.2

WBS 1.1

WBS 2.2

WBS 1.1

WBS 1.2

   

WBS 1.2

Grouping WBS el. 3

WBS 1.2

     

WBS 2.1

 

WBS 2.1

     

Grouping WBS el. 1

 

WBS 2.2

     

Grouping WBS el. 2

 

Grouping WBS el. 1

         

Grouping WBS el. 2

         

Grouping WBS el. 3

         

Grouping WBS el. 4

         

Grouping WBS el. 5

Assigning the Materials to Grouping WBS Elements in MRP

The finished product is not allowed to be planned with requirements grouping. It is therefore planned with the WBS element.

The assembly underneath the finished product is planned with the grouping WBS element 1, 2 or 3, if its MRP group has been assigned to the grouping WBS elements and the WBS elements, which have caused the requirements, have been correctly assigned.

The materials in the BOM levels underneath this assembly, on the other hand, are planned with the grouping WBS elements that are correspondingly lower in the hierarchy, if the MRP groups are assigned to the grouping WBS elements and the WBS elements are assigned as displayed in the table. Important raw materials in the example above are planned with grouping WBS element 6. This also applies if the raw material is used for the final assembly and therefore a dependent requirement is at the highest BOM level.

Materials from the lowest BOM level (usually less important raw materials) are not planned using requirements grouping but rather as collective requirements.