PDKM

The PROMISE PDKM is an extremely important component of a PROMISE application. Its purpose is to systematically integrate and manage data from all lifecycle phases, creating knowledge from information.

The most significant differentiator between the data managed in a PDKM and PLM data managed in a more traditional PLM data repository is that the PDKM can integrate and consolidate detailed data about the life of each individual instance, i.e. about each unique serial number, of a product series, rather than simply data about the characteristics of the series itself.

The PDKM will incorporate data from PEIDs and other software systems, e.g. legacy CAD, CRM and/or SCM systems that are already part of a company’s IT infrastructure. If data from these systems is required for generating specific decision support information, it can be made available to the PROMISE Decision Support System. The ultimate goal of the PDKM is to integrate data throughout the entire lifecycle from different sources, allowing comprehensive analysis and enhancement of such data using one or more DSS systems. The more detailed insight on products thus obtained enables the enhancement of operational business processes.

The initial step in defining the semantic object model of the PDKM system was the analysis of user requirements defined by all of the application scenarios in the EU PROMISE Project. At the same time, an analysis of the relevant industry standards in the field of product life cycle data modelling was carried out. This study provided many useful ideas for the development of the semantic model.

Relationship to existing standards

The most relevant standards that were analyzed are:

  • STEP
  • STEP NC
  • PLCS
  • MANDATE
  • PLM XML
  • ANSI/ISA-95

These standards have some properties and features in common, but are also distinguishable by many remarkable differences. First of all, they were designed by different organizations, with different scopes and for different targets.

STEP, STEP NC, PLCS and MANDATE can at first sight be grouped together, because they are all ISO (International Organization for Standardization) standards; furthermore, PLCS is an application protocol of STEP.

STEP is an industry standard for product data representation and it is composed of several parts (application protocols) whose aim is to focus on a specific industrial context. There are application protocols for product design, for mechanical and electrical engineering, for sheet-metal manufacturing, for product assembly, for the automotive industry, etc.

PLM XML is an open standard developed mainly by EDS (Electronic Data Systems Corporation) and dealing with the product design phase.

ISA-95 is an ANSI (American National Standard Institution) standard, except for its first part, ANSI/ISA-95.00.01, which is also an ISO standard (ISO 62264-1). All together, ANSI/ISA-95 Parts I, II, and III describe the interfaces and activities between an enterprise’s business systems and its manufacturing control systems: it mainly focuses thus on the area corresponding to the production phase of a product.

One more remark concerning another interesting standard is PLM Services, which is not included in the list given above because it focuses on the exchange of product “type” life cycle data; so it is mainly focused on the design. The underlying data model itself is compliant to STEP AP214.
Standards throughout Life Cycle Phases

In the adjacent figure, the life cycle phases of interest and their association to the studied standards are shown. The figure also illustrates that none of the standards considered covers the whole product life cycle. The BOL, MOL and EOL phases are represented, as in the PROMISE vision.

The BOL phase is divided into two parts: the Product Development phase and the Product Supply phase. The first one is about the design and development of the product; here the physical product does not exist, it is only an idea represented on drawings and design information. Lots of standards focus here; the PLM XML and STEP standards were chosen among the others because of their breadth, importance and the fact they are “open” standards.

The Product Supply phase is about the production of the physical product, the management of its supply chain and of its delivery to the final customer. Some of the most interesting standards that focus on this phase are ISA-95, MANDATE, STEP NC, and PLCS. However some of them focus more on the production phase, such as STEP NC, some other on the delivery and none can be seen as “complete” in the sense stated above.

For the MOL phase more or less specialized standards exist, such as again MANDATE and PLCS among those studied here. The same holds for the EOL phase, which is dealt with by PLCS and STEP.

The General System Object Model (PDKM Semantic Model) is described in detail in Volume 4 of the PROMISE Architecture Series "Architecture Reference: PROMISE PDKM System Object Model"