I’m looking for an efficient way to calculate the date each member of a team is available given a set of project assignments. There are 25 team members, each with a set of capacities and assignments.
Capacities are a percentage availability between two dates (this is how part-time hours are supported, 100% being full-time), with null end dates for scenarios where the capacity is indefinite. Capacities can be zero, to support things such as secondments or parental leave.
Assignments link a team member to a project for a percentage between two dates. This allows a member to have two projects at the same time (say a 60/40 split) and these add up to the capacity of the team member. So if a person has 60% capacity, they might have two projects 30% each.
All of this works perfectly, but now I want to calculate the date each person in the team is available next. I can do this in what feels like a brute-force way by using a loop to count forward one day at a time until I arrive at a point where the total assigned percentage is less than the capacity, but this feels wildly inefficient – is there a better way?
I’ve added a Gantt chart image to show what I mean, I’d like to calculate the dates where the red lines are. Any help, even pseudo-code, is greatly appreciated. The application stack is NodeJS and Vue, and I’m using the Luxon library in the brute-force method. Language doesn’t matter, I’m looking for help with the general approach to the problem that I can then implement in JS.
