Natural Language Processing of Textual Use Cases

Master's thesis

Advisor: Vladimír Mencl
Author: Jaroslav DraÂľan

Abstract

Use cases [1] written in natural language are usually employed for specifying functional requirements. VladimĂ­r Mencl in [4] employed state-of-the-art linguistic tools (mainly English parser[2]) to extract behavior specification of a system under design from textual use cases. The behavior specification is described in the form of pro-cases [5]. His work [4] shows that this is possible but he met several issues. In this thesis, we solve some of the issues. We propose an algorithm based on the Mencl's algorithm which allows to process more use cases than the Mencl's one and we describe a metric which evaluate quality of a parse tree.

Goals

• The first goal is to propose a metric to evaluate how much the parse tree matches the rules for a use case sentence. The metric helps us to select the best parse tree from those we obtain by employing two or more parsers to parse a use case sentence. This should minimize the risk that a use case step analysis returns no or incorrect pro-case action because a single parser has returned an incorrect parse tree of the use case step.
• The second goal is to propose an algorithm based on [4] which enables processing more use cases than the Mencl's one. There is no exact guideline for use case writing but only some recommendations [1, 3] which can be sometimes contradictory. This causes that many use cases do not match the SVDPI (subject ... verb ... direct object ... indirect object) pattern. Thus, they cannot be transformed by the algorithm proposed in [4]. The proposed algorithm should address mainly the following problems: A use case step starts with a condition, a use case sentence describes more than one action, or contains more than one direct and/or indirect objects.

Current Status

The thesis has been successfully defended on Feb 6, 2006, and is now publicly accessible and available for download.

Download

Resources available for download:

• Text of the thesis: [PDF]
• Proof-of-the-Concept implementation (source, binaries, examples): [ZIP]

You may also wish to access the original thesis proposal.

References

[1] Cockburn, A.: Writing Effective Use Cases, Addison-Wesley Pub Co, ISBN: 0201702258, 1st edition, Jan 2000

[2] Collins, M: A New Statistical Parser Based on Bigram Lexical Dependencies., Proceedings of 34th Annual Meeting of the Association for Computational Linguistics, ACL 1996, 24-27 June 1996, University of California, Santa Cruz, California, USA, Morgan Kaufmann Publishers, 1996, http://people.csail.mit.edu/mcollins/code.html

[3] Larman, C.: Applying UML and Patterns: An Introduction to Object-Oriented Analysis and Design and the Unified Process, Prentice Hall PTR, ISBN: 0130925691, 2nd ed, 20013

[4] Mencl, V.: Deriving Behavior Specifications from Textual Use Cases,in Proceedings of Workshop on Intelligent Technologies for Software Engineering (WITSE04, Sep 21, 2004, part of ASE 2004), Linz, Austria, ISBN 3-85403-180-7, pp. 331-341, Oesterreichische Computer Gesellschaft, Sep 2004

[5] Plasil, F., Mencl, V.: Getting "Whole Picture" Behavior in a Use Case Model, in Proceedings of IDPT 2003, Austin, Texas, U.S.A., Dec 2003, ISSN 1090-9389