Writing a spec without being a developer

Quotes get vague when the enquiry is vague. That is rarely down to missing expertise on the client side. Usually a few details are missing that nobody thought were important.

The three sentences that help most

If nothing else makes it into the enquiry, please these three:

1. Who uses this, and how many of them? "Twelve people in the back office" leads to a completely different system than "our roughly 4,000 customers".
2. What happens instead today? The existing route (even if it consists of a spreadsheet and three phone calls) is the most accurate description of the requirement that exists.
3. How would you know it had worked? That answer separates the necessary from the desirable.

What else belongs in it

• Existing systems that need to be talked to: ERP, accounting, time tracking. Interfaces are almost always the part that takes longer than planned.
• Data volume and origin. Is there legacy data to migrate? What state is it in?
• Roles and permissions. Who may see, who may change, who may approve?
• Deadlines with a reason. "By the trade fair in September" is usable. "As soon as possible" is not.
• The frame. An order of magnitude is enough. It is not a negotiating position but the information that decides whether we are talking about an extension or a new build.

What you can leave out

Technical requirements with no reason behind them. If a particular database is already running and maintained in your business, that is a sensible constraint. A technology somebody read about in an article only narrows the field.

Likewise: fully formulated solutions. A described problem leaves room for a simpler route. A described solution does not.

A usable skeleton

A one-page enquiry is enough in most cases:

• Situation: what happens today, and what is wrong with it
• Goal: how success would be recognisable
• Users: who, how many, with what background
• Surrounding systems: what has to be connected
• Frame: deadline, budget range, hard constraints
• Open questions: what you do not know yet yourself

The last point is the most valuable. An enquiry that names its open questions leads to a more honest quote than one that fakes certainty.