CCE Theses and Dissertations

Date of Award


Document Type


Degree Name

Doctor of Philosophy in Information Systems (DISS)


Graduate School of Computer and Information Sciences


Sumitra Mukherjee

Committee Member

Maxine S Cohen

Committee Member

William L. Hafner


Case-based, Help-desk, Rule-based


This exploratory study investigates the hypothesis that case-based reasoning (CBR) systems have advantages over rule-based reasoning (RBR) systems in providing automated support for Tier-2 help desk operations. The literature suggests that rule-based systems are best suited for problem solving when the system being analyzed is a single-purpose, specialized system and the rules for solving the problems are clear and do not change with high frequency. Case-based systems, because of their ability to offer alternative solutions for a given problem, give help-desk technicians more flexibility. Specifically, this dissertation aims to answer the following questions:

1. Which paradigm, rule-based or case-based reasoning, results in more precise solutions to problems when compared to the solutions derived from system manuals?

2. Which paradigm, rule-based or case-based reasoning, is more convenient to maintain in terms of knowledge modification (i.e. addition, deletion, or modification of rules/cases)?

3. Which paradigm, rule-based or case-based reasoning, enables help-desk technicians to solve problems in shorter time, and therefore at lower cost?

This is an exploratory study based on data collected from field experiments. RBR and CBR based prototypes were set up to support Tier-2 help desk operations. Trained help desk operators used the system to solve a set of benchmark problems. Data collected from this exercise was analyzed to answer the three research questions.

This exploratory study supported the hypothesis that the case-based paradigm is better suited for use in help desk environments at the Tier-2 level than is the rule-based paradigm. The case-based paradigm, because of its ability to offer alternative solutions for a given problem, gave the help-desk technician flexibility in applying a solution. Alternatively, the rule-based paradigm provided a solution if, and only if, a rule existed for a solution meeting the exact problem specifications. Further, in the absence of a rule, problem research time, using the rule-based paradigm, extended the time required to formulate a solution thereby increasing the cost.

This research provided sufficient information to show that the help-desk knowledge based system utilizing the case-based shell provided better overall solutions to problems than did the rule-based shell.

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