What it depends on
Predictability isn't something you install: it's the result of three things being in place at the same time. Take one away and the forecast becomes an opinion.
- A process with defined stages and objective criteria for moving forward
- Reliable data on what is in each stage, right now
- Historical conversion between stages and cycle time
How to calculate it, in its simplest form
Multiply the value in each pipeline stage by that stage's historical conversion rate to close, then add up the results — factoring in cycle time to know what fits within the period.
Refinement comes later: breaking it down by source, by sales rep, by deal size. But that's the foundation, and it's already enough to stop making decisions based on hope.
Why almost no one has it
Because it depends on every other piece being in place. It's the last problem in a sales operation to get solved — which is why it's usually the most cited goal and the least achieved.