Design and Conceptual Development of Shop Floor Controllers Through the Manipulation of Process Plans

Published

August 1, 2002

Author(s)

Hyunbo Cho, Y J. Son, Albert T. Jones

Abstract

A shop floor control system (SFCS) performs the decision-making and execution functions necessary to fill production orders efficiently. To cope with a variety of dynamic factors, the SFCS must be able to perform these functions in real-time. This paper proposes a way to reduce the cost of developing the software that implements this real-time requirement. It describes a design and development framework that uses hierarchical process plans and simulation. The plans are written in the process specification language (PSL) developed at NIST and exchanged using extensible markup language (XML) document type definitions (DTDs). The decision-maker in each controller parses these DTDs into a non-linear graph, resolves the AND-junctions and OR-junctions, determines a sequence of production tasks, and generates the set of messages to execute those tasks. The decision-planner, when called by the decision-maker, evaluates several control rules using a corresponding simulation model, chooses the most promising from that set, and provides it to the decision-maker. The proposed concept enables control software to be designed and developed in terms of the evolution of process plans, so both the decision-maker and the executor can be partially generic and the simulation model (decision-planner) can be partially generated in an automatic manner.

Citation

IIE Transactions on Design and Manufacturing

Pub Type

Journals

Keywords

cell control, decision-making, process plan, shop floor control, simulation

Citation

Cho, H. , Son, Y. and Jones, A. (2002), Design and Conceptual Development of Shop Floor Controllers Through the Manipulation of Process Plans, IIE Transactions on Design and Manufacturing (Accessed May 12, 2024)