The adoption of agile software development methodologies has been a necessary evolution to support the explosive demand for new and expanded capabilities. There is no doubt that without the broad adoption of agile practices much of the growth in technology, and all of those aspects of everyday life that is driven by technology, simply would not have happened.
Still, too much of a good thing applies. Another old adage that comes to mind is “You can have it better, cheaper, faster. Pick any two”. Many organizations have insisted on all three. How did they do it? They sacrificed the documentation.
I’m not talking about saving shipping costs and trees by making manuals virtual, and then saving bandwidth by replacing the documents download with the install files with links to online documentation (which has its own issues in this world of massive M&A). I’m talking about all those wonderful references that development teams, sometimes backed by technical writers, produced so that others may pick up where they left off to maintain and enhance the final applications. Yes, that documentation.
Self-Documenting Code does not make a Self-Documenting Solution
While no one can honestly disagree with the value put forth in the Manifesto for Agile Software Development : “Working software over comprehensive documentation”, I also don’t think the intention was that documentation impedes working software. Still, the manifesto has fed the meme (the original definition, not the funny GIFs) “Good code is self-documenting”. When I hear this, my response is “True; and knowing what code to read for a given issue or enhancement requires documentation”. My response lacks the desired impact for two reasons: It doesn’t easily fit on a bumper sticker and it requires putting time and effort into a task that many people do not like to do.
The danger of little or no documentation is that the application becomes dependent on “tribal knowledge”. In a perfect enterprise, this is a dependable approach because employee turnover is low and when people do depart they always do so with adequate notice and thoroughly train their replacements. I have heard these enterprises exist, though I have never spent any time working with one of them. I did, however, recently work with a business intelligence group where their entire ETL staff departed within a few weeks of each other after a few years of furiously building hundreds of data integrations in a dozen different business areas and then spent less than 9 hours in “knowledge transfer” sessions with my team who were tasked with keeping the lights on until a new crew was hired and trained. There was not one page of documentation at the start of the knowledge transfer and I have yet to find a line of documentation in any of the code.
I’m not advocating the need for waterfall-style detailed design documents. In some ways, those can be worse than no documentation because they are written before the code and configurations they are intended to describe are created and fail to be updated when the actual implementation deviates. In an agile world, writing the documentation after the implementation is a sound approach that will support the manifesto value of “Working software over comprehensive documentation” by being just enough documentation to facilitate maintaining the software in the future.
Meeting between the Lines
How much is just enough? That is going to vary by both application (and/or system) and enterprise. Some applications are so simple that documentation in the code to supplement the “self-documenting” style is sufficient. More complex solutions will need documentation to describe things from different aspects, and the number of aspects is effected by whether maintenance is done by the development team or a separate production support group. The litmus test for whether your documentation is adequate is to take a look at it from the perspective of someone who has never heard of your application and needs to be productive in maintaining or enhancing it in less than a day. If you have difficulty in adopting that point of view (many people do, and double as many developers), have someone outside your team review the documentation.
I find the following types of documents to be a minimum to ensure that a system can be properly managed once released to production:
- Logical System Architecture
- Physical System Architecture
- Component Relation Diagrams
- Deployment Procedures
Again, the level of detail and need for additional documentation is going to be driven by complexity and experience. Another factor is how common the relevant skills are. If the candidate pool for a particular platform or framework is shallow, more detail should be provided to act as springboard for people that may be learning the technology in general while diving into the particular implementation.
Yes, there are Exceptions
Conversely, some solutions are true one-offs that are filling a very specialized need that is unlikely to evolve and may have a short lifespan. These implementations only really need sufficient reference to migrate them to another environment or decommission them to free up resources while not negatively impacting other systems. I do caution you to really be sure that an application falls into this category before deciding to minimize the documentation. What comes to my mind when I think of such decisions is massive amount of resources dedicated to dealing with two-digit years in 1999 to address applications that were not expected to still be in use when they were developed 10 or 20 years previously.
A Final Appeal
At the beginning I agreed with the manifesto value of working code prioritized over comprehensive documentations. In the days when most software life cycles began with tons of documentation and meetings to review the documents and meetings to review the results of the review, a great deal more beneficial build and test activities could have been done in that time instead. My experience in documenting the results of agile and other iterative processes toward the end of the development cycle and then reviewing that documentation with people outside the team is that design flaws are discovered when looking at the solution as a whole rather than the implications to individual stories in a sprint. The broader perspective that waterfall tried to create (and often failed since most waterfall documentation does not match the final implementation) can be achieved better, cheaper and faster when documenting at the end of the epic. In this one case, picking cheaper and faster yields better.
Documenting the fruits of your software and application implementation labors may not be the most exciting part of your team’s work, but the results of not documenting can become the most painful experience for those that follow…or your next gig!
Originally published at InfoWorld