Prior to this Product is responsible for outlining User Stories based on the learnings from the Discovery & Definition phase.
Here at Uptech Studio we aren't big believers in estimates. In fact we generally don't believe or trust in estimates. But our clients need to be able to budget and plan, not down to a date or week even. But they need to have an understand of relatively large time range and budget range to find out if they can even afford to pay us and if the timeline will work for their business need.
So we use this as an opportunity to have the Tech Lead start to think through all the stories and what is going to be involved with them and estimate the story at the scale of indivdual developer worker days. This is generally done in Airtable.
We then sum up all the working days and add a multiplier based on confidence and unknows using around 1.5 and 2 to account for the fact that estimates are generally over optimistic.
These numbers can then be used to compute roughly time range and cost range based on these estimates.