Many thanks to the Eurostar folk allowing me to present the webinar, “Live Specifications: From Requirements to Automated Tests and Back”. This talk describes how we think companies can implement continuous delivery and live specifications using the Behaviour-Driven Development approach and redistributed testing.
There were some interesting questions posed at the time some of which I answered, but several I didn’t. I’ve finally got around to writing some notes against each. See below…
Q: How to convince client to agile?
Well, the reasons for going Agile are well understood now. The critical arguments (from my point of view) are:
- Breaking larger projects into smaller ones reduces the complexity and risks of managing delivery – if a small project fails – it fails fast and cheaply.
- Agile encourages the use of autonomous multi-skilled teams who communicate well. Decision making delays are much reduced, feedback is fast so problems are corrected quicker and more cheaply.
- An on-site customer (often known as the product owner) provides day to day direction for projects, so technical people don’t go off track, and get feedback on ‘the right thing to do’ quickly.
- Breaking complex functionality into stories allows stories to be prioritised by business value (by the on-site customer). As a consequence, the team always delivers value as early as possible and are not distracted by lower value activities.
- The morale of Agile teams is usually much higher than other organisations because all members are involved, well-informed and accountable for progress towards delivery.
- Agile does not necessarily reduce the amount of rework, but brings it forward so the consequences of defects are minimised. Further, refactoring is usually an explicit task for developers in Agile teams, so the reword due to redesign and discovery of better ways to do things is visible and manageable.
Q: BDD works very well for testing stories and component testing, e.g. web services, but when considering end-to-end scenario testing, BDD gets very messy. What do you suggest when testing scenario based end-to-end tests?
True enough. The current BDD tools focus very much at a story or feature-level testing and automation but do not support the ‘end to end’ testing required to test integration and consistency between features.
The BDD approach needs to align more with the increasing use of workflow and story-boarding approaches used by teams building non-trivial systems. Essentially, feature test scenarios need to be mapped to steps in a workflow so they become an executable end to end test procedure. Now, this is relatively easy with manual tests run by intelligent testers. But there are some specific challenges with automating these end to end tests.
Existing BDD tools can usually work with GUI automation tools, but more often, they are used with unit test frameworks. In general, they fit more naturally with developers’ feature testing than system or user acceptance testing. In order to create end to end tests:
- Each feature/scenario test requires a context to be defined by the controlling workflow OR the feature/scenario needs keywords/macros that can be called to prepare the feature for use in different scenarios. It’s not yet clear which approach is best (or even viable, without too much manual effort).
- Existing keyword-driven test tools and frameworks map nicely to BDD. It seems to me that the keyword driven approach for navigation through (potentially complex) workflows is the most likely path to success with end to end automation. Watch out for BDD capabilities in existing frameworks e.g. Robot Framework has a BDD capability.
- In our tool, Business Story Manager, we already have the capability to create process-paths or workflows with steps mapped to features and scenarios. We have ‘integration to Robot Framework’ on our roadmap. Other integrations will follow.
- Overall however, we expect most automated testing to focus on feature-based checking, rather than complex end to end testing with obscure paths.
Q: Does a BDD dictionary replace an acceptance test plan ?
In a word, no. I’m not sure I understand the question. In the Business Story Method and supporting technology, the dictionary has several core features:
- To capture terms (and concepts) that are relevant to an application and requirements. These may be business or technical terms, abbreviations or any concept, even business rules.
- To index the usage of these terms in requirements, stories and tests so they can be traced and coverage analyses made.
- We extend this in our tool to cover data item names in scenario outlines. Where scenarios contain <placeholders> for data provided as tabulated examples we can trace the usage of these data items and in effect create a simple, but effective data dictionary for them.
- Overall – the goals of the dictionary are to promote a ubiquitous language, support traceability, impact analysis and provide requirements and story coverage measures that are based on the language used in the business domain.
Q: Could you name again the BDD tools you mentioned as an example at the beginning of the webinar?
There is a comprehensive description of BDD on the http://behaviourdriven.org website. The section on Implementations provides a list of the common tools, although I think the list is growing steadily. http://behaviourdriven.org/Implementations
The tools I mentioned in the talk were Cucumber, Specflow and FitNesse, I believe.
Q: I have tried to google DeFOSPAM but got no hits.
It’s there for me 8O). Try http://gerrardconsulting.com/index.php?q=node/604 – this text is an extract from the pocketbook.
Q: In BDD, when scenarios become more and more, how to organize them effectively?
It’s an obvious problem with stories, once you create non-trivial systems using them. We have heard tales of companies managing 20,000 stories in separate feature files in a single directory, and that’s a scary prospect. One way with existing ‘file-based’ products would be to create a consistent file naming convention and directory structure. But this is really cumbersome.
The Relish website http://relishapp.com offers a simple repository service for your stories (and other documentation) and is free for ‘open’ projects. Expect other services like this to spring up.
Q: In regards to production vs going live, how to you avoid customers being exposed to changes in production?
Increasingly, the continuous delivery model implies that software and changes are delivered into a production (or production-like) environment for testing prior to go live. There are several approaches that can be used including:
- Feature toggling (http://en.wikipedia.org/wiki/Feature_toggle) essentially, a flag in the software, can be set to turn features (that may not be complete) on or off at will.
- So called ‘dark releases’ – whereby features are released to production but are not advertised or accessible through the normal user interface, but could be accessed by testers using special urls and passwords, for example. Sometimes called ‘back doors’, these are useful for testers but are also of interest to hackers J
- A ‘blue-green’ release implements two parallel environments in production. One is live and the other is for evaluation. When the evaluation version has been checked out, routers can be flipped to reroute traffic to the new version (and flipped back in case of problems).
- Limited releases and Canary releases are where a software version is released to only a subset of users in a particular country, region or network or to a subset of production servers for evaluation. Users may or may not be aware of such trials. If a problem occurs, only a subset of your users are affected (and a rapid rollback can be effected).
In all cases, a reliable and rapid roll-back facility is required to avoid the wrath of users affected by a faulty release. These approaches are discussed in Jez Humble and David Farley’s excellent book, “Continuous Delivery”.
Q: So you suggest testers to be more like business analysts and to help product owners to refine requirements, right?
I’ve suggested that business analysts and testers should look to using a critical thinking discipline to prepare stories and scenarios to illustrate features, derived from requirements. Scenarios can be used to drive reviews of requirements by exampling them. The DeFOSPAM approach is a simple method of deriving stories and scenarios for this purpose.
Now, testers are not alone in having critical thinking skills or a touch of scepticism. It may be that business analysts perform the story-generation and requirements validation role. But the scenarios can also define a set of required acceptance tests for features. In this case, the testers might be better placed to create them.
Our recommendation is that stories and scenarios are created to achieve this dual goal. By so doing, requirements are improved, developers get concrete examples of features in use and a minimal set of test cases they can choose to automate through a BDD approach. In principle, all feature checks could be provided as scenarios for developers to automate so that later testers can be relieved of some or all of this error-prone chore.
There is an opportunity for testers to perform early story and scenario preparation to reduce the amount of later manual checking. The time saved may mean fewer testers are needed. What better incentive is there to get involved early?
Q: What if the requirements are potential needs that users might require? No one will know until it is out in the real world.
If a requirement describes a ‘nice to have’, sham, vanity or useless feature and it is not challenged at the requirements stage, then it is possible that it will be developed and delivered, tested and deployed – and never used. This is more likely in a structured or outsourced development. In an agile team, one would have thought this is much less likely.
Regardless of approach however, the task of creating a feature description and scenarios is like a paper prototype. The “as a.. I want … so that …” construct drives out an owner, a need and a purpose for the feature. It challenges the stakeholder motives: “who will use it? What does it do? And why?” The chances are this highlights a dud feature, or at least challenges its viability.
If a feature makes it through this stage, then the “given … when … then …” scenarios provide an opportunity challenge the feature using real-world concrete examples. The sceptical analyst, developer or tester can use the scenarios to ask, “what if…?” and suggest some good, bad, contradictory, anomalous or just plain meaningless consequences.
The act of story creation can be viewed as a ‘thought experiment’ to speculate on how the feature may stand up to real world operation. It is, in effect, a proxy or prototype, much cheaper to test than a delivered feature for acceptance.
Q: What if you have a vague requirement? What if requirements change over time?
In the case of a vague requirement and the developer has nothing better to work from, then the developer is likely to guess at the requirement, or make unsafe assumptions, or invent solutions that bear little relation to the real need. Perhaps they know the business domain and deliver something useful. But the risk of getting it completely wrong is probably too high to bear.
Creating stories to illustrate a feature specified in a requirement triggers some difficult questions for stakeholders. The DeFOSPAM mnemonic represents seven key questions:
- What do the words of the requirement mean? (Definition)
- What features are being specified? (Features)
- What outcomes can be identified? (Outcomes)
- What situations or scenarios must the feature deal with? (Scenarios)
- Does the requirement predict sensible outcomes? (Prediction)
- Is the text of the requirement ambiguous? (Ambiguity)
- Has anything been left out of the requirement? (Missing)
The DeFOSPAM process forces the stakeholder to articulate a requirement more clearly.
To the question, “What if the requirement changes over time?” one has to ask in response, “Why does it change?”
In some cases, the business need changes. Well, there’s not much we can do about that one except negotiate the changes and cost of change with stakeholders. More often, requirements change because the *perception* of the need changes. One could look at a software project as a learning experience for stakeholders. They might propose some vague requirements initially, and wait for the developers to deliver some software for the stakeholders to evaluate. Having some experience of a solution in use, the stakeholders then say, “that’s great, but what I really want is…”
This process works, but my, it is frustrating for everyone on the team, especially the developers and testers whose time is wasted. How can we shortcut this process? By giving stakeholders examples of the proposed system in use through a prototype, wireframes and examples. Creating stories and scenarios coupled with steps in a workflow, with perhaps wireframes to give them a feel for what features might look like can trigger the same learning process, but at a much lower cost.
So, the answer is really to accelerate the learning process by providing rapid, meaningful feedback through example and improve the requirements and associated stories so they are trusted. Trusted does not mean perfect. In the Business Story Pocketbook (p 31), “A trusted requirement is one that, at this moment in time, is believed to accurately reflect the users’ need, and sufficiently detailed to be developed and tested”.
Q: What is the best tool for requirement management? What are the most important features a tool should have to be used in SDLC?
There are many, many RM tools out there, and it would be unreasonable to promote any one of them, and requirements can comprise many different models as well as the most common textual description. But from the ‘Live Specification’ point of view and covering functional requirements only (and excluding the obvious needs to be easy to use, flexible etc.) these features seem to be key:
- The functional requirement encompasses a ‘statement of need or business rule’ (the traditional requirement) plus associated features, scenarios and examples. Think of this as ‘specification AND example’.
- A dictionary of terminology, abbreviations, synonyms, antonyms, data names, business rules and an index of use throughout the requirements content.
- Traceability from business goals through requirements, features scenarios and examples to allow business impact analysis. A change at any level can be traced up or down the hierarchy.
- Reporting of requirements content in a format understandable to stakeholders, at any level of the hierarchy so that a review of goals versus requirements, requirements versus features/scenarios can be supported.
- Integration of features and scenarios with a test execution management, test automation framework or BDD tool so that requirements content drives testing and development, and test status can be reflected up the hierarchy from scenarios through features, requirements and business goals.
- Needless to say, accessibility to everyone in a business or project team, version and change history, access control.
Q: How will the business see “more testing” in the initial phase? How to convince the business that tester will now start “testing” requirements and less integration tests (after the development team delivers)?
I’ve tried to explain above how the exampling and validation of requirements using business stories has some significant benefits. The trade-off is that it requires a change of emphasis in the behaviours of analysts, developers and testers and collaboration between all three. But you know what? Productive Agile teams have reminded us that software development is most effective when it is treated as a collaborative process.
The change required is that Testers need to collaborate with both business analysts (to be involved earlier and contribute their critical skills to creating stories and scenarios) and with developers (to provide coherent scenarios for automation of feature checks).
The payoffs are significant:
- Business stories provide early feedback so vague, ambiguous and incomplete requirements can be trusted to reflect the true need.
- Business stories and scenarios provide clear ‘feature acceptance criteria’ but can also be a covering set of feature checks that can be automated by professional developers.
- Automated feature checks support both the Behaviour- and Test-Driven Development approaches so development is less error-prone; they also provide candidate regression tests to be used for the lifetime of the feature.
- Automated feature checking reduces the need for labour intensive and error-prone, expensive (and boring) manual checking so test teams can focus on the more subtle end to end and obscure tests.
- Delivery timescales become more reliable and the quality of delivered software is higher.
- Using tools that provide the traceability, better business impact analysis becomes possible – changes can be properly evaluated – at last.
- New and meaningful test coverage measures based on the language and terminology used by stakeholders become viable.
There are an increasing number of companies moving towards continuous delivery, live specification, BDD and redistributed testing etc. To my knowledge, there are no objective, comparative studies or metrics demonstrating benefits and value for money of these approaches. I doubt there ever will be. But a growing number of practitioners are acquiring positive experiences of these approaches and environments. Well-known software gurus and fast-growing service companies are promoting them with vigour.
I have to say, with this momentum and backing, you should expect these methods to proliferate over the next few years.