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Re-Thinking System-Level Testing – A Vision – Paul Gerrard-->
In the first essay in this series, I set out the challenges of system-level testing in environments where requirements documents define the business need and pre-scripted tests drive demonstrations that business needs are met. These challenges are not being met in most systems development projects.
In this second essay, I’d like to set out a vision for how organizations could increase confidence in requirements and the solutions they describe and to regard them as artifacts that are worth keeping and maintaining. Creating examples that supplement requirements will provide a better definition of the proposed solution for systems developers and a source of knowledge for testing that aligns with the business need.
I need to provide some justification.
The response of some to the challenge of capturing trusted requirements and managing change through a systems development project is to abandon the concept of pre-stated requirements entirely. The Agile approach focuses on the dynamics of development and the delivered system is ‘merely’ an outcome. This is a sensible approach in some projects. The customer is continuously informed by witnessing demonstrations or having hands-on access to the evolving system to experience its behaviour in use. By this means, they can steer the project towards an emergent solution. The customer is left with experience but no business definition of the solution – only the solution itself. That’s the deal.
But many projects that must work with (internally or externally) contracted requirements treat those requirements as a point of departure, to be left behind and to fade into corporate memory, rather than as a continuously available, dynamic vision of the destination. In effect, projects simply give up on having a vision at all and are driven by the bureaucratic needs to follow a process and the commercial imperative of delivering ‘on time’. It’s no surprise that so many projects fail.
In these projects, the customer is obliged to regard their customer test results as sufficient evidence that the system should be paid for and adopted. But the content of these tests are too often influenced by the solution itself. The content of these tests – at least at a business level could be defined much earlier. In fact, they could be derived from the requirements and ways the users intend to do business using the proposed system (i.e. their new or existing business processes). The essential content of examples is re-usable as tests of the business requirements and business processes from which they are derived. Demonstration by example IS testing. (One could call them logical tests, as compared with the physical tests of the delivered system).
The potential benefits of such an approach are huge. The requirements and processes to be used are tested by example. Customer confidence and trust in these requirements is increased. Tested, trusted requirements with a consistent and covering set of examples provide a far better specification to systems developers: concrete examples provide clarity, improve their understanding and increase their chances of success. Examples provide a trusted foundation for later system and acceptance testing so reusing the examples saves time. The level of late system failures can be expected to be lower. The focus of acceptance tests is more precise and stakeholders can have more confidence in their acceptance decisions. All in all, a much improved state of affairs.
Achieving this enlightened state requires an adjustment of attitudes and focus by customers, and systems development teams. I am using the Test Axioms (http://testaxioms.com) to steer this vision and here are the main tenets of it:
1. Statements of Requirements, however captured, cannot be trusted if they are fixed and unchanging.
2. Requirements are an ambiguous, incomplete definition of business needs. They must be supported by examples of the system in use.
3. Requirements must be tested: examples are derived from the requirements and guided by the business process; they are used to challenge and confirm the thinking behind the requirements and processes.
4. Requirements, processes and examples together provide a consistent definition of the business need to be addressed by the system supplier.
5. The business-oriented approach is guided by the Stakeholder and Design Axioms.
6. Examples are tests: like all tests, they have associated models, coverage, baselines, prioritisations and oracles.
7. Business impact analyses during initial development and subsequent enhancement projects are informed by requirements and examples. Changes in need are reflected by changes in requirements and associated examples.
8. Tests intended to demonstrate that business needs are met are derived from the examples that tested the requirements.
9. Requirements and examples are maintained for the lifetime of the systems they define. The term ‘Live Specs’ has been used for this discipline.
If this is the vision, then some interesting questions (and challenges) arise:
1. Who creates examples to test requirements? Testers or business analysts?
2. Does this approach require a bureaucratic process? Is it limited to large structured projects?
3. What do examples look like? How formal are they?
4. What automated support is required for test management?
5. How does this approach fit with automated test execution?
6. What is the model for testing requirements? How do we measure coverage?
7. How do changing requirements and examples fit with contractual arrangements?
8. What is the requirements test process?
9. How do we make the change happen?
I’ll be discussing these and other questions in subsequent essays.