Constructing a tree or matrix to analyze and document goals and requirements helps to clarify the goals and document the thought process.
Beginning with an obvious fundamental truth or goal provides a solid, unchallengeable foundation. If your analysis doesn’t begin with a fundamental truth you need to work your way up the tree until you find the true fundamental requirement.
A very common error is to consider decisions and assumptions to be requirements. A requirements tree which begins with “add nifty techy features to the product” is misleading. A need for new features is a common assumption. The new features may be a decision as a result of some conscious or unconscious thought process, but most often the perceived need for new features is an assumption resulting from personal infatuation with nifty high-tech features.Engineers and programmers seem to universally perceive increasing complexity to be more elegant and valuable than simplicity.
Constructing a requirements tree which begins with a fundamental truth and derives detailed requirements logically can clearly show secondary requirements and decisions.
Top Level Requirements Tree
For most business purposes “Make Money” is a fundamental undeniable truth and therefore a good beginning. Make money by “Selling Widgets” is the first decision or assumption. The true requirement is make money. Selling widgets is one way to make money. Subsequent requirements are derived from the decision to sell widgets. Placing the assumption that we are sellers of widgets in the diagram as an obvious decision or assumption allows questioning this fundamental assumption. Maybe we should lease widgets, or if we’re Google, maybe we should slap an ad on the widget and give it away.
Technical features- where many people prefer to begin- are third or fourth level decisions and may be lower priority than cost or market placement.
The process is also creative. Notice that- without going anywhere near a book on marketing- we’ve just about derived marketing’s infamous 5 P’s (7 P’s or 8 P’s in recent books.) Promotion, placement, price, performance, positioning, product are all suggested from the requirements.
