Software Engineering Institute

This paper presents a method for applying the PROxy Based Estimation (PROBE) technique to Structured Query Language (SQL). Estimating program size is a critical component of successful software project effort estimation and cost estimation. The PROBE technique is a simple estimation method that can be used for estimating program size and effort. To date, PROBE has been used more often to estimate programs written in third-generation programming languages (3GL) such as C, C++, and Java. Its application to IT development has been inhibited by the lack of demonstrated applicability to database work. For data storage, most IT departments have transitioned from file-oriented storage (accessed by traditional 3GL languages) to relational database server software, which uses an implementation of 4GL languages such as SQL to manipulate data. SQL's logic encapsulation properties differ dramatically from those of traditional 3GL languages, so it is not clear to most developers how to effectively apply the PROBE techniques to SQL. The method presented here enables a level of estimation detail similar to the application of PROBE to traditional 3GL languages.