A SYSTEMATIC APPAROACH TO ASSESSING AND EXTENDING GRAPHICAL MODELS OF MANUFACTURING
Gintautas Bronius Jazbutis
A systematic approach to assessing current graphical modeling methods, and for extending one, was proposed. This approach consists of four major steps: 1) Define requirements; 2) Assess current modeling methods; 3) Design modeling method; 4) Evaluate and Validate designed modeling method. A set of requirements for modeling manufacturing systems, and material handling within them, was developed. A representative set of existing graphical modeling methods was evaluated against these requirements; strengths and weaknesses were identified. IDEF0 was chosen as a suitable for extension. A design method was used to extend IDEF0 systematically. Several graphical constructs were added to IDEF0s syntax: distinct information flows; resources used to move flows; storage locations for material items; decision points in the sequence of processes; and a rearranging of the layout of process boxes to indicate a more precise sequence of events. Several forms were also added to capture information about the processes, resources, decisions, storage locations, and information and material object flows. Together, these additions, make for the modeling method JDEF. JDEF was evaluated against two case studies and promises to be a useful method for modeling manufacturing systems. The overall approach taken is promising in the development of all-new graphical modeling methods, in addition to extending an existing one, as was done in this research.