I'm a bit confused by this Forced Assign concept, are they forcing you to work a day off, or is this only the case if you answer the phone by mistake?
The company 'sells' the months work to the pilot community and we, through bidding, agree to achieve the flying programme.
Some people bid high for high credit months and some people bid low. There are always some uncovered trips for which there are those who don't achieve their selected bid or don't place a bid, otherwise known as 'blindline' holders. The company constructs the blindlines from the remaining trips and then allocates them to the blind line holders after both bidding stages are completed.
The new 'Force Assign' stage takes any uncovered trips after stage 1 and stage 2 and the blind line construction and allocates them to pilots who have not achieved CAP and have the space for the uncovered work on their line. Failing this a given trip line may be wiped for favour of work coverage.
The upshot is that, in days gone past, you could bid for a line and be allocated the trip line thus knowing what you were getting about 3 weeks in advance. You could, with hours of unpaid overtime in your 'bank' bid low for a month using a 'bank' withdrawl to get time off thus leading to flexibility and work life balance.
That has all now disappeared. Even with a CAP line you can be force assigned, a process which appears about 10 days before the end of the month.
Once the rosters are published they are, generally, set in stone and a very lively swapping culture exists leading to you often swapping half the month out for more beneficial trips.
Not an ideal solution in my opinion.