Jeremy Matson

Assessing the responsiveness of existing production operations

Production responsiveness refers to the ability of a production system to achieve its operational goals in the presence of supplier, internal and customer disturbances, where disturbances are those sources of change which occur independently of the system’s intentions. A set of audit tools for assessing the responsiveness of production operations is being prepared as part of an EPSRC funded investigation. These tools are based on the idea that the ability to respond is linked to: the nature of the disturbances or changes requiring a response; their impact on production goals; and the inherent response capabilities of the operation. These response capabilities include information gathering and processing (to detect disturbances and production conditions), decision processes (which initiate system responses to disturbances) and various types of process flexibilities and buffers (which provide the physical means of dealing with disturbances). The paper discusses concepts and issues associated with production responsiveness, describes the audit tools that have been developed and illustrates their use in the context of a steel manufacturing plant.

Development of algorithms for agent based control of manufacturing flow shops

This paper reports on a development process for determining a suitable algorithm for application within agent based shop floor control systems. In particular, the algorithm discussed here is focussed on the achievement of high and consistent levels of production throughput in a manufacturing flow shop environment where there is a significant degree of flexibility associated with route selection. It is intended that in addition to performing well under nominal operating conditions, that such algorithms support a control system that is robust in the face of typical but unexpected process disturbances, such as congestion. It is emphasised that the algorithms are primarily intended for shop floor control and execution rather than scheduling for which numerous existing algorithms already exist.

Emergent flow shop control based on mascada agents

Abstract New concepts for manufacturing control are required to allow faster responses to unanticipated operational disruptions and reconfigurations. This paper presents a new approach based on agent technology to gain both disturbance and change management capabilities. In this scheme, agents operate within an information distribution environment as observable in biological insect societies and the overall control behavior emerges from the decision taking of single agents. It is shown how to specify the right set of agents for a control application, how these agents are coordinated in their behavior and how decision making takes place.

Distributed Co-ordination of Steel-Making Operations for Reduced Production Stoppages

Abstract This paper reports on the development of algorithms for factory decision-making and scheduling systems. The particular decision-making and schedule co-ordination problem studied relates to the synchronisation of a series of events in the context of a production changeover in electric arc steel-making. The paper explores two distributed approaches to this co-ordination problem. The first is a simple manual algorithm that helps co-ordinate the behaviour of steel-plant production via (i) the exchange of relevant inter-unit process information and by (ii) recommending operators take appropriate local actions. The second approach provides a framework for a more general class of problems, and supports either a partially or fully automated co-ordination approach. It is based on an approach from the field of distributed artificial intelligence, referred to as Partial Global Planning (Durfee 1988).