The Challenge of Material Revision Management
In the manufacturing industry, the revision management of materials, bill of materials (BOM) and documents is a daily task. Companies mainly use the logistical function Engineering Change Management (ECM) in order to document changes to production-related data. This general function is available in the standard software, “SAP, Enterprise Resource Planning (ERP)” within the module , “LO-ECH”. The functionality supports changes of relevant objects such as materials, BOM’s, task lists or documents with exact documentation at an attribute level. An example reveals how this works in practice:
If there is a reconstruction of the holes of a perforated plate of the object type material, the CAD drawing has to be adapted. This is documented by increasing the revision level of the CAD drawing. If the perforated plate is part of an BOM, all dependent materials must also be revised. The adaptation of the CAD document and the BOMs takes place in the ERP system in the “ERP Central Component (ECC)”. However, if a company has a master data system in place, the material change is governed by its governance. The material, or alternatively its revision level, is not adapted in the ERP, but rather in the master data system, for example SAP MDG. If data like the CAD drawing of a perforated plate is changed and revised, this also applies to the material master data record. This parallel change is mandatory, because it is the only way to prevent data inconsistencies. Therefore, as soon as an object is revised with a change number, its data is automatically linked in ECC and MDG via the revision level of the ECM. Here it is important that attributes of the material do not necessarily have to be changed in order to increase the revision level. The SAP system provides this functionality as a standard feature. However, a look at the concept of product lifecycle management (PLM) which is widespread used in the manufacturing industry, reveals why an integration between ECM and MDG that goes beyond the standard is useful.
According to the PLM concept, every material has a status that describes the current phase of life. The material is managed in the master data system. The possible documents as well as BOMs in which the material is relevant are maintained in the ECC. Let’s assume that a material has the status “active” in the PLM, and it has to be changed for production-related reasons. An ECM is in use, which documents the changes with support of the change number. The change number created in the ECM is assigned to the material, and its revision level is increased in MDG. For a change of material, the PLM concept considers a status change to be necessary, for example to “in revision”, since this information is important for production. It can thus be decided, for example, that only urgent orders are produced. Less urgent orders can wait for the release of the new revision.
The requirements for BOM changes are more complex. If a material in the lower manufacturing level changes, the revisions go right through the entire production depth in the ECC. This means that all affected materials in MDG have to be changed at the same time.
The interaction becomes more interesting when the master data system is operated as an independent system (HUB scenario). Here, it must be ensured that the change number master is distributed to all systems that are allowed to manage revisions. The status concept also has to be taken into consideration when PLM is used. This is the only way it is possible to manage the revisions of the relevant objects, such as a material for example, across heterogeneous systems.
The interaction between ECM and MDG taking the product lifecycle management into consideration is anything but trivial. To be able to perform material revision management across different systems, it is mandatory to gain a complete overview at an early stage and develop a complete integration concept.
by Felix Schneider, Camelot ITLab GmbH
The article was first published in German on Allaboutsourcing.de