DylanSmith had an interesting forum comment on the SFTS website

He tracks actual time using the SFTS template through appropriate use of the Estimated Effort and Work Remaining fields. The idea is that if you want to enter X hours of actual time against a SBI you have to decrease the Work Remaining by Y and/or increase the Estimated Effort by Z such that Y+Z == X.

For example, lets say I had an SBI with an Estimated Effort (EE) of 5 hours, and a Work Remaining (WR) of 5 hours.

Day 1: Actual time spent on SBI is 3 hours. Change WR to 2. (Y = 3, Z = 0, Y+Z = 3).

Day 2: Actual time spent on SBI is 3 more hours, and I’m still not complete, probably about 1.5 hours remaining still on this SBI. Change WR to 1.5, Change EE to 7.5 (Y = 0.5, Z = 2.5, Y+Z = 3).

Using this method I can report on actual time, it is simply EE – WR.