Hj Henk Jan Pels

Collaborative systems for production management

Supply chain management means the coordination of all material and information flows throughout the entire value chain. The main goal is to organise the overall process of the supply chain to achieve an optimum in costs and time, for example, by improving the following four Figures, such as increasing capacity utilization, decreasing inventories, decreasing lead time and increasing delivery reliability and adherence to delivery dates. The conventional control of supply chains pursuit top-down planning approaches to coordinate the supply flows (incl. material and infom1ation), run by current ERP systems, between the different enterprises participating in a supply network. Collaborative supply net management has technological and non-technological aspects. From the non-teclmological point, aside from willingness to organisational changes, a feeling of tmstful partnership must evolve. On the technological side, agent technology is proposed as being indispensable to achieve integration of Advanced Planning Systems (APS) across company borders. Thus, this paper proposes an agent-based approach to collaborative supply net management, based on the SCOR-Model (Supply chain Operations Reference-mode!). Finally an example is given that sketches the idea of an agent-based simulation approach to tackle the bullwhip effect

Decomposition of information systems for production management

Abstract This paper approaches the issue of decentralization and decomposition of information systems from two angles, viz. from an organizational and from an infological point of view. Current information systems tend to become more and more integrated. However, this integration causes organizational complexity, which, in turn, becomes prohibitive for organizational change. Thus, there is a need for decomposition of the information system from an organizational point of view. A strategy for such a decomposition in a production environment is given.

Flexibility in manufacturing: an architectural point of view

The objective of this paper is to present the influence of some architectural choices on the flexibility of a manufacturing control system. Architectures play a variety of roles in the redesign of manufacturing systems. Evolving technology and an increasingly demanding manufacturing environment have been accompanied by an evolutionary growth in control architectures. We present a number of architectural paradigms and their application in a model factory, which is based on a real life PCB assembly plant. Flexibility is determined, to a large extent, by the architectural design. However, its achievement may be limited by the technology that is used for implementation. Guidelines are needed that prescribe when certain architectural principles should be applied.

Classification hierarchies for product data modelling

Abstraction is an essential element in data modelling that appears mainly in one of the following forms: generalisation, classification or aggregation. In the design of complex products classification hierarchies can be found product families that are viewed as classes of product types, while product types are seen as classes of product instances. So far data models, if they support levels of classification, do not support the inheritance of product properties the way product family hierarchies are supposed to. This paper proposes an interpretation of the member of construct that enables one to define inheritance in classification hierarchies. Unified modelling language (UML) static structures are used as data modelling language. A textual notation is added that enables the introduction of data structures and corresponding data contents in the course of an analysis.

Modelling Production Management Systems

Abstract This review of the IFIP working conference on “Modelling Production Management Systems”, held in Copenhagen, August 29–31, 1984, attempts to show the threads in the actual development of the science of production control. The major aim of flexibility can only be achieved by simplification and decentralization of the control structure. This requires the introduction of adapted models for production control, organization analysis and information systems development. Simulation is a promising tool, but the introduction is retarded because of problems concerning the validation of simulation models and the integration of simulation models with production databases.

Defining the Customer Dimension of PLM Maturity

Product lifecycle management (PLM) adoption includes very extensive changes in intra- and inter-organizational practices and requires new types of skills and capabilities. A controlled PLM implementation can therefore be very challenging in practice. PLM maturity models, often at least partly based on the thinking of CMM (Capability maturity modeling) can be used to make the implementation of PLM a better approachable and a more carefully planned and coordinated process. Our objective was to enhance current maturity modeling approaches on PLM implementation, and we have argued for and presented a novel PLM maturity dimension, ”customer dimension”, that we consider as an important addition to current PLM maturity models.

Evaluation of architecture design with CIMOSA

This paper evaluates the suitability of the CIMOSA modelling framework for the specification of control architectures for manufacturing systems. An architecture can be seen as a set of specifications that express the functions of components and their interfaces. Based on the characteristics of architectures, several requirements on architecture modelling techniques are defined. These requirements are used in the evaluation, which is illustrated by an industrial application. CIMOSA offers adequate constructs to specify concurrent processes and their interactions, and to specify process behaviour. The framework separates architectural concerns from implementation matters and provides multiple views. Dynamic constraints, which are used to non-deterministically specify system behaviour, can not be represented. In addition, the semantics of the formal model reveal some inconsistencies. The CIMOSA modelling framework is now accompanied by some methodologies that aim to guide the user in the application of the framework.

A conceptual modeling technique for discrete event simulation of operational processes

A formal modeling technique, based on colored timed Petri net and UML static structure modeling languages is used to teach students to model their business process problem as a discrete event system, before they build a working simulation model in a simulation tool (in our case Arena). Combining Petri net and UML static structure diagrams, one can build an abstract, well defined and complete model. This model enables the simulation analyst to make an unambiguous, complete and yet easily readable model of the target operational process. The two most important classes of decisions that are reflected in the conceptual model are the choice of the real world details to be taken in or left out the model and the precise specification of the output parameters of the simulation. This paper describes the modeling technique and discusses its value in teaching and in the formulation of decision problems regarding operational processes.

Federated Product Data Management in Multi-company Projects

An approach for enabling concurrent engineering between companies by providing a proper collaboration platform, as developed in the VIDOP project is proposed. Apart from security, information status is an important element of trust. However, status-coding schemes differ much between companies and are deeply anchored in local engineering culture. An abstract life cycle model that enables comparing and relating different life cycle conventions is presented. A federated PDM architecture is proposed that enables interface with the local PDM systems in a loosely coupled, but yet effective way.

Proactive Engineering and PLM: Current Status and Research Challenges

This paper discusses about the evolution of Product Lifecycle Management (PLM) through the introduction of an emerging vision in engineering design, proactive engineering. Over the last two decades, engineering design has seen some relevant approaches covering sequential engineering and then concurrent engineering (CE). Indeed, this shift was required to encompass knowledge integration issue into product design stages. This has led to relevant approaches such as design for X, parametric design, PLM-based approaches, decision-making support and ontology-based approaches to name a few. Proactive engineering can be considered as an emerging engineering framework which integrates as early as possible lifecycle knowledge and technological constraints in product design and manage those knowledge in an integrated and harmonious manner. The fact of using lifecycle process knowledge as design context demands therefore the definition of downstream processes before defining he product geometry so as to overcome current limitations in CE oriented PLM approaches. Hence, with such stakes, understanding and awareness becomes crucial in PLM in order to deliver well-balanced products.