Aysin Rahimifard

The enhanced use of enterprise and simulation modellingtechniques to support factory changeability

Bearing in mind that activity requirements of manufacturing enterprises (MEs) can usefully be described as a network of dependent processes, the current paper identifies complementary properties of state-of-the-art enterprise modelling and simulation modelling techniques. It is observed that, when these techniques are used in a coherent fashion, they have potential to create semantically rich models of process networks that can be computer-executed so as to replicate and/or predict organizational behaviours. The current paper describes an outline of how a particular choice of well-proved enterprise modelling and simulation modelling techniques can be used in an integrated fashion. Also described are interim research findings when using such an integrated modelling approach in a case study furniture making company. For key segments of business processes currently deployed by the case study company, the outcome has been new qualitative and quantitative understandings about (a) alternative ways of organizing multi-product flows through a constrained (in situ) set of human and technical resources and (b) potential performance enhancements that could be achieved in process segments by purchasing, commissioning and deploying alternative systems of human and technical resources. Research groundwork is now in place to support the case study company as in the future it makes (a) medium-to-long term investment decisions about new manufacturing control strategies and the purchase of new resource systems and (b) short-to-medium term production planning and control decisions.

A web-based information system to support end-of-life product recovery

Abstract Increased public awareness towards global environmental problems has forced manufacturing companies to consider the negative impacts of their activities on the environment. In this context, the effective management of products at the end of their useful life has become of paramount importance due to the ever-increasing national and international legislation and directives aimed at making take-back and recovery of used products obligatory for the original equipment manufacturer. This highlights a need for a systematic approach for enhancement of information, business and production management systems to deal with additional activities and processes related to the recovery of products. The research reported in this paper has developed a five-stage methodology to support product end-of-life management within manufacturing companies. The modelling and design of appropriate product recovery information systems, which constitute the main core of this methodology, are also described. The paper concludes with the description of an application of this methodology and information system design for the recovery of cutting tools at the end of their useful life in metalworking applications.

A computer integrated unified modelling approach to responsive manufacturing

Computer modelling approaches have significant potential to enable decision-making about various aspects of responsive manufacturing. In order to understand the system prior to the selection of any responsiveness strategy, multiple process segments of organisations need to be modelled. The article presents a novel systematic approach for creating coherent sets of unified enterprise, simulation and other supporting models that collectively facilitate responsiveness. In this approach, enterprise models are used to explicitly define relatively enduring relationships between (i) production planning and control (PPC) processes, that implement a particular strategy and (ii) process-oriented elements of production systems, that are work loaded by the PPC processes. Coherent simulation models, can in part be derived from the enterprise models, so that they computer execute production system behaviours. In this way, time-based performance outcomes can be simulated; so that the impacts of alternative PPC strategies on the planning and controlling historical or forecasted patterns of workflow, through (current and possible future) production system models, can be analysed. The article describes the unified modelling approach conceived and its application in a furniture industry case study small and medium enterprise (SME).

A structured modelling approach to simulating dynamic behaviours in complex organisations

This article reports a case study application of a systematic approach to modelling complex organisations, centred on simulation modelling (SM). The approach leads to populated instances of complementary model types, in ways that systematically capture, validate and facilitate various uses of organisational understandings, knowledge and data normally distributed amongst multiple knowledge holders. The model-driven approach to decision making enables improved manufacturing responsiveness. Literature on modelling technologies relevant to manufacturing systems organisation design and change is presented, as is literature on production planning and control. This provides a rationale for the development of a new modelling methodology which combines the use of enterprise, causal loop and SM. Subsequently, this article describes how in the case of a specific manufacturing enterprise the combined modelling techniques have informed the choice of alternative production planning and control policies. An example enterprise model of a capacitor manufacturing company is illustrated as derivative causal-loop models that structure and enable the design and use of a general purpose simulation model.

Integrated approach to modelling human systems as reuseable components of manufacturing workplaces

A new approach to modelling human systems as reusable components of manufacturing workplaces is described. Graphical and computer executable models of people competences and behaviours are created which are qualitatively and quantitatively matched to equivalent models of process networks, decomposed into roles and dependencies between roles. To enable model creation and reuse, coherent sets of role, competence and dynamic producer unit (DPU) modelling concepts have been defined and instrumented using enterprise modelling (EM), simulation modelling (SM) and causal loop modelling (CLM) techniques. This paper reports on an application of the modelling approach to create related models of ‘process oriented roles’ and ‘candidate human systems’ so as to systemise matching of role requirements to resource systems attributes and to inform aspects of strategic and tactical decision making in an SME making composite bearings.

Simulation Based Organizational Change In Multiple Product Assembly Systems

During the last few decades, Manufacturing Enterprises (ME) have been facing increasingly volatile market conditions due to changes such as globalisation, reduced product lifetimes and increased competition. Simulation modeling (SM) has been widely deployed to help MEs optimise their operations by assessing uncertainties and possible future organizational behaviours. This paper reports ongoing research study which is developing and testing the use of a unified set of SM concepts within the context of Enterprise Modelling (EM) to facilitate process oriented organizational change related to the planning and control of ME’s operations. Case study research findings are described which focus on optimizing multi-product flows through assembly shop resources available to a furniture making SME based in UK.

Reference Configurations to Support the Implementation of the Product Recovery Supply Chain

Increased public awareness towards the global environmental problems together with government regulations has forced current manufacturing companies to be more conscious of the effect of their activities on the natural environment. One of the many efforts to combat these environmental problems is to recover products at the end of their life in order to conserve natural resources, minimise energy consumption and reduce waste disposal problems. Recently an increasing number of manufacturing enterprises aim or are forced by legislation to adapt product recovery into their existing business practices. This has highlighted a need for a systematic approach for enhancement of information, business and production management systems to deal with additional activities and processes related to the recovery of products. The research reported in this paper aims to provide a clear understanding of such product recovery activities by extending the traditional manufacturing supply chain through the definition of a product recovery implementation methodology an its application via two reference Configurations.