WHO DOES THE TESTING?

 Software testing is not a one person job. It takes a team, but the team may be larger or smaller depending on thesize and complexity of the application being tested. The programmer(s) who wrote the application should have areduced role in the testing if possible. The concern here is that they're already so intimately involved with the productand "know" that it works that they may not be able to take an unbiased look at the results of their labors.  

Testers must be cautious, curious, critical but non-judgmental, and good communicators. One part of their job is toask questions that the developers might find not be able to ask themselves or are awkward, irritating, insulting or eventhreatening to the developers. 

♦ How well does it work? 

♦ What does it mean to you that "it works"? 

♦ How do you know it works? What evidence do you have? 

♦ In what ways could it seem to work but still have something wrong?

 ♦ In what ways could it seem to not work but really be working? 

♦ What might cause it to not to work well?

A good developer does not necessarily make a good tester and vice versa, but testers and developers do share atleast one major trait—they itch to get their hands on the keyboard. As laudable as this may be, being in a hurry tostart can cause important design work to be glossed over and so special, subtle situations might be missed that wouldotherwise be identified in planning. Like code reviews, test design reviews are a good sanity check and well worth thetime and effort.

Testers are the only IT people who will use the system as heavily an expert user on the business side. User testingalmost invariably recruits too many novice business users because they're available and the application must beusable by them. The problem is that novices don't have the business experience that the expert users have andmight not recognize that something is wrong. Testers from IT must find the defects that only the expert users will findbecause the experts may not report problems if they've learned that it's not worth their time or trouble. 

Key Players and Their Roles

Business sponsor(s) and partners

 ♦ Provides funding

 ♦ Specifies requirements and deliverables

 ♦ Approves changes and some test results  

Project manager 

♦ Plans and manages the project 

Software developer(s) 

♦ Designs, codes, and builds the application 

♦ Participates in code reviews and testing

 ♦ Fixes bugs, defects, and shortcomings 

Testing Coordinator(s)

♦  Creates test plans and test specifications based on therequirements and functional, and technical documents

Tester(s) 

♦  Executes the tests and documents results

THE V-MODEL OF SOFTWARE TESTING

 Software testing is too important to leave to the end of the project, and the V-Model of testing incorporates testing intothe entire software development life cycle. In a diagram of the V-Model, the V proceeds down and then up, fromleft to right depicting the basic sequence of development and testing activities. The model highlights theexistence of different levels of testing and depicts the way each relates to a different development phase.  

Like any model, the V-Model has detractors and arguably has deficiencies and alternatives but it clearly illustrates thattesting can and should start at the very beginning of the project. (See Goldsmith for a summary of the pros and consand an alternative. Marrik's articles provide criticism and an alternative.) In the requirements gathering stage thebusiness requirements can verify and validate the business case used to justify the project. The businessrequirements are also used to guide the user acceptance testing. The model illustrates how each subsequent phaseshould verify and validate work done in the previous phase, and how work done during development is used to guidethe individual testing phases. This interconnectedness lets us identify important errors, omissions, and otherproblems before they can do serious harm. Application testing begins with Unit Testing, and in the section titled"Types of Tests" we will discuss each of these test phases in more detail.