XML-based requirements engineering for an electronic clearinghouse * Mariusz A. Fecko * , Christopher M. Lott Applied Research Area, Telcordia Technologies, Inc., One Telcordia Dr RRC-1L326, Piscataway, NJ 08854, USA Received 3 May 2004; revised 15 January 2005; accepted 20 January 2005 Available online 31 May 2005 Abstract We present methods and tools to support XML-based requirements engineering for an electronic clearinghouse that connects trading partners in the telecommunications area. The original semi-structured requirements, locally known as business rules, were written as message specifications in a non-standardized and error-prone format using MS Word. To remedy the resulting software failures and faults, we first formalized the requirements by designing an W3C XML Schema for the precise definition of the requirements structure. The schema allows a highly structured representation of the essential information in eXtensible Markup Language (XML). Second, to offer the requirements engineers the ability to edit the XML documents in a friendly way while preserving their information structure, we developed a custom editor called XLEdit. Third, by developing a converter from MS Word to the target XML format, we helped the requirements engineers to migrate the existing business rules. Fourth, we developed translators from the structured requirements to schema languages, which enabled automated generation of message-validation code. The increase in customer satisfaction and clearinghouse-service efficiency are primary gains from the investment in the technology for structured requirements editing and validation. q 2005 Published by Elsevier B.V. Keywords: GUI; Message-processing; XML; Business rules; Requirements engineering 1. Introduction We present experience with the requirements engineer- ing process for an electronic clearinghouse. The clearing- house [33] connects multiple trading partners in the telecommunications area. Competitive local exchange carriers (CLECs) use the clearinghouse to communicate information about their customers and orders to wholesale telecom suppliers, the incumbent local exchange carriers (ILECs). This information is passed between trading partners using intricately structured messages. The primary benefit to CLECs of using the clearinghouse is that they have to conform only to the clearinghouse’s interface specification; they are shielded from the wide variation among their wholesale trading partners’ interfaces. Fig. 1 shows message-processing flow in the clearinghouse. At the outset of this project, clearinghouse requirements engineers wrote message specifications called ‘business rules’ in MS Word 1 files using a semi-structured tabular format. To get a sense of the size of the requirements, one ILEC trading partner may accept 30C messages, any one of which requires 200C pages in an MS Word document. The users of the requirements documents include systems engineers who generate various downstream documents, developers who implement the clearinghouse services, testers who ensure message processing conforms to the requirements, and customers (e.g. CLECs). One of the challenges facing the project was a high degree of variation in the requirements documents: there was no standardized way of specifying the intricacies of messages. Staff turnover only exacerbated the situation. As a result, users of the requirements documents needed many clarifications, and often made mistakes while using the requirements. Thus, inconsistencies and errors in the requirements resulted in software failures and faults, which contributed to a high rate of modification requests (known as MRs, essentially bug reports), and significantly eroded the profitability of the service. Another challenge 0950-5849/$ - see front matter q 2005 Published by Elsevier B.V. doi:10.1016/j.infsof.2005.01.005 Information and Software Technology 47 (2005) 841–858 www.elsevier.com/locate/infsof * Copyright q 2005 Telcordia Technologies, Inc. All rights reserved. * Corresponding author. Tel.: C1 732 699 2720 fax: C1 732 336 7015. E-mail address: mfecko@telcordia.com (M.A. Fecko). 1 MS Word is a trademark of Microsoft Corporation.