Skip to main content

Overemphasis on Functional Requirements

I've mentioned before that there are two kinds of requirements, functional and nonfunctional. What I didn't mention is that most organizations place too much emphasis on functional requirements.

How can you tell if your organization overemphasizes functional requirements?

If your organization bothers to document requirements (whether in an MRD or other document), examine them. If you find any of the following statements apply, then your organization probably is overemphasizing functional requirements:
  1. Is there a laundry list of product features?
  2. Are there more use cases than constraints on the use cases?
  3. Is there a multi-page section labeled "functional requirements"?
If any of these statements apply in your case, then your organization likely fails to understand the difference between functional and nonfunctional requirements. In a future entry, I will explain why the overemphasis on functional requirements has a negative impact on product development.

UPDATE: See the follow-up entry and this clarification. The problem is that so-called functional requirements are sometimes functional design specifications masquerading as requirements.

Comments

leathej1 said…
I see where you are going with this. However, let me turn this upside down and suggest we concentrate on Using Functional Requirements More Effectively. I think you will find that NF requirements will fall right off the page if we follow some simple steps to drive detail and context in our Functional Requirements.
Roger L. Cauvin said…
But isn't "detail and context" precisely what nonfunctional requirements are?
leathej1 said…
Right. So why let your BAs procrastinate with statements like this:

Non-functional requirements:
Non-functional requirements will be dealt with in another document.

IOW - why the hell do we deal with them separately?
Roger L. Cauvin said…
I agree. Since nonfunctional requirements modify (or constrain) functions, it doesn't make sense to deal with them separately.

Popular posts from this blog

Why Spreadsheets Suck for Prioritizing

The Goal As a company executive, you want confidence that your product team (which includes all the people, from all departments, responsible for product success) has a sound basis for deciding which items are on the product roadmap. You also want confidence the team is prioritizing the items in a smart way. What Should We Prioritize? The items the team prioritizes could be features, user stories, epics, market problems, themes, or experiments. Melissa Perri  makes an excellent case for a " problem roadmap ", and, in general, I recommend focusing on the latter types of items. However, the topic of what types of items you should prioritize - and in what situations - is interesting and important but beyond the scope of this blog entry. A Sad but Familiar Story If there is significant controversy about priorities, then almost inevitably, a product manager or other member of the team decides to put together The Spreadsheet. I've done it. Some of the mos

What Product Managers Can Learn from the Apple iPod

The Story When Apple unveiled its iPod digital music player back in October 2001, I dismissed it as a  parity product . I already owned the Cowon iAUDIO CW100 MP3 player, loaded with my favorite tunes. There was Apple, generating great hype over the iPod as if it were a breakthrough product. The idea of a portable digital music player was nothing new. The first mass-produced MP3 players came out in 1998. In late 2001, the concept may have been new to a lot of Apple customers, but it wasn't new to me. I proudly showed my MP3 player to friends when they gushed about the iPod. Thus Apple's iPod was not an innovative product in and of itself. Years later, however, I realized the significance of ecosystem of which the iPod was a part. Apple had released iTunes (with technology purchased from  SoundJam MP ) and created the iTunes Store for finding and downloading music. Unlike Napster , it was a safe and legal way of distributing and acquiring music. The prior way of playing

Stop Validating and Start Falsifying

The product management and startup worlds are buzzing about the importance of "validation". In this entry, I'll explain how this idea originated and why it's leading organizations astray. Why Validate? In lean startup circles, you constantly hear about "validated learning" and "validating" product ideas: The assumption is that you have a great product idea and seek validation from customers before expending vast resources to build and bring it to market. Indeed, it makes sense to transcend conventional approaches to making product decisions . Intuition, sales anecdotes, feature requests from customers, backward industry thinking, and spreadsheets don't form the basis for sound product decisions. Incorporating lean startup concepts , and a more scientific approach to learning markets, is undoubtedly a sounder approach. Moreover, in larger organizations, sometimes further in the product life-cycle, everyone seems to have an opinio