| An improved approach to material selection in the flexible packaging of foods was developed as a part of this dissertation. The system developed combines conventional expert system technology with the decision-making approach of the analytic hierarchy process.; The expert system portion of the work represents the rule-based approach of materials selection in the flexible packaging industry in six sub-markets: dry beverages, liquid beverages, condiments, confection, dairy products and snacks. There are over 300 rules in the system. Databases are used for storage of deeper domain knowledge rather than create additional levels of backward chaining to establish the properties of packaged goods. The laminated layers of the user-chosen structure are selected in a systematic way. Both the chemical nature and the quantity (in thickness or weight per area) are determined by the system. Structure properties, such as permeabilities (based on Fick's law), are calculated along with material cost. In this domain, this is the first expert system of this capability and magnitude.; The analytic hierarchy process module is a series of additional programs that can be enabled or disabled based on the mode selected by the user. When the AHP mode is enabled, the system allows the user to select and rank criteria from cost, permeabilities (oxygen and water vapor), capacity concerns, competitive concerns and environmental concerns. Then, when running the expert system, the user can select multiple structures. The expert system then selects materials and calculates properties for all selected structures. Then, ABP (matrix eigenvector) techniques are used to rank the structures using the user's selected preferences.; The expert system portion was tested against the developer and against an expert panel of four experts. It recommended valid structures for 97% of the cases. The ABP portion was tested for appropriate sensitivity to changes in user perspective and proved to be capable of changing its ranking in this case. |
