Guideline: In More Details - Development Test

Characteristics of testers and developers

The table below [Pettichord, 2000] sums up a number of salient characteristics of testers and developers:

Testers	Developers
Get up to speed quickly	Thorough understanding
Domain knowledge	Knowledge of product internals
Ignorance is important	Expertise is important
Model user behaviour	Model system design
Focus on what can go wrong	Focus on how it can work
Focus on severity of problem	Focus on interest in problem
Empirical	Theoretical
What’s observed	How it’s designed
Sceptics	Believers
Tolerate tedium	Automate tedium
Comfortable with conflict	Avoid conflict
Report problems	Understand problems

Influence of the technical implementation

In system development, increasing use is being made of so-called services. A service in this connection can be seen as an ‘independent’ repeatable business task, such as “Check credit rating” and “Open new account”. Services are set up as modular and usually small applications that can be found, accessed and used by other applications, without knowledge of these being required as regards the underlying technical implementation of the service.

A Service Oriented Architecture (SOA) is a framework for integrating business processes and supporting IT infrastructure as secure, standardised components – services - that can be reused and combined to address changing business priorities [Bieberstein, 2005].

The increasing use of distributed systems with large numbers of components and services places high demands on the quality of the individual components or services. The complex collaboration between all these components and services makes the finding of the source of a defect very difficult and time-consuming. The result of integrating qualitatively inadequate components or services into the system and hoping that the defects will be found by the system or acceptance tests will be that the required system quality (on time and within budget) cannot be delivered. The technical nature of many components and services means that the development tests bear a heavier responsibility for establishing that the separate components or services are of sufficient quality before they are integrated.