Why a fixed price can't be given in advance
Custom business software isn't a ready-made product on a price list. Two seemingly similar needs, for instance “order management” at two different companies, can require very differently sized solutions depending on what systems the company already has, how much data moves, and how many people use the solution.
Principle: scope the smallest working solution first
Instead of pricing the whole imagined end state at once, it's worth scoping the smallest whole that does the needed job properly first. This smaller scope also makes the price easier to estimate, because the extent is clear and doesn't yet contain unimplemented assumptions.
A clear proposal before implementation
Before starting implementation, you should always get a written, clear proposal for what's being built and what the price is based on. The proposal must state what will be done, what won't be done at this stage, and how a change in scope during the work would affect the price.
What affects the price
- How many separate work steps or views the solution covers
- Whether the solution needs to connect to the company's existing systems (integrations usually increase scope)
- How much data needs to be moved, checked or converted into a format that fits the new solution
- Whether the solution is needed for one person or for several roles
- How well the current way of working is already described: the better it's known what's slow or error-prone in the current way, the faster the solution can be scoped correctly
How to proceed
- Briefly describe which work step is difficult or slow today.
- Tell us which systems your business already uses.
- Ask for a proposal where the scope and price are limited to the first working version, not the whole imagined end state.