QA

Software Testing Fundamentals

Software Testing Fundamentals—Concepts, Roles, and Terminology

John E. Bentley, Wachovia Bank, Charlotte NC

ABSTRACT

SAS® software provides a complete set of application development tools for building stand-alone, client-server, and Internet-enabled applications, and SAS Institute provides excellent training in using their software.  But making it easy to build applications can be a two-edged sword.  Not only can developers build powerful, sophisticated applications, but they can also build applications that frustrate users, waste computer resources, and damage the credibility of both the developer and SAS software.  Formal testing will help prevent bad applications from being released, but SAS Institute offers little guidance related to software testing.  For those unfamiliar with the topic, this paper can serve as a primer or first step in learning about a more formal, rigorous approach to software testing.  The paper does not address any specific SAS product and may be appropriate for even experienced application developers.

INTRODUCTION

With SAS and Java, talented developers can do incredible, wonderful things.  AppDev Studio™ provides a full suite of application development tools for building client-server and Internet-enabled applications.  With Base SAS software, SAS/Connect®, and SAS/Share® as a foundation, developers can easily build a 'thick-client' application using SAS/AF® and SAS/EIS® to access data and share information across a LAN.  For 'thin-client' Internet-enabled applications SAS provides web/AF™, web/EIS™, SAS/IntrNet®, and SAS® Integration Technologies.

In the hands of less talented developers, these same tools can still do incredible things but not always wonderful things.  Everyone has used poorly-designed, clumsy, frustrating applications that are only barely able to get the job done.  This is not an indictment of entry-level developers—everyone was a rookie at one time, and often it's not their fault anyway.  This author believes that the finger is better pointed at those responsible for training the entry-level developer and, even more so, at those responsible for overseeing the testing and release of their work.  In many cases, however, the problem may be a systemic or scheduling failure—overly aggressive schedules to document requirement, design, build, test, and release software may leave too little time for adequate testing and force developers to release code that isn't ready.

Assuming that a project has fully collected and clearly documented its business and technical requirements (which might be a stretch, but let's pretend), a primary cause of failed application software development is lack of a formal requirements-based testing process.  "Formal requirements-based testing" may conjure up an image of a lengthy, involved, and minutely detailed process but it doesn't necessarily have to be like that, although in organizations with mature software engineering practices or at CMM level 3 it probably is.  In many if not most organizations, formal software testing can easily be tailored to the application being examined and has only two real prerequisites.

♦   Business requirements and design documents that allow development of a test plan

♦   People who understanding how to write and carry out a test plan

Collecting and documenting business requirements is outside the scope of this paper, so here we will say only that clear, concise, and measurable requirements are essential not only to developing the application itself and creating a test plan but also gauging if the final product meets the users' needs.

"It is not enough to do your best.  You must know what to do and then do your best."

W. Edwards Deming