Update from Paul

[paulgilles]

Quick Update because I am not gonna be at the meeting today.

What I have done

I implemented Target Working Hours on the Branch "Combining Constraints". Some quick infos about that branch

• returns solutions depending on combination of constraints
• allows to enable target working hours
• free days of employees will be subtracted from target hour per employee. (If you are on vacation 10 days, you do not need to work less).
• Todos: I need more information about the employees. Ideally we have access to the Soll Time which would take care of vacation days automatically. Is this possible?

I build in that one can change the constraints not only in SWITCH in the code, but also as arguments. That makes it easier when submitting those computations to a computer cluster. SWITCH does work also, if arguement in command is not set.

I tested different combinations of constraints. What I have found:

• Target Work + Min Number of Staff: 40 min, solutions (see attachment)
• Target Work + Min Number + Free Days: No Solution, Some employee only work half the days? is that correct?
• Target Work + Min Staff + (min_night_seq | more_free_night_worker | max_consecutive | rotate): solutions and relativly fast (<10mins) => having objective function helps
• Target Work + Min Staff + Free Weeksends: No Solution. This is surprising! Free Weekends should be a soft constraint, should not restrict the solution space (does it? ? => Ask Johanna). This needs to be checked. Are there any additional hard constraints set, fucking long (2h +)

Statistics
  - Conflicts     : 56587703
  - Branches      : 177080049
  - Wall time     : 13440.13s
  - Solutions found: 0

• Target Work + Min Staff + 24h no shift after Night shift: I dont know, already runs for 2:17h

Summary:

• Target Working Minutes conflicts with free days -> This is weird. We need to understand how vacation days and SOLL works?
• Target Working Minutes combined with some constraints runs relativly fast: Good Combination for debugging purposes
• Free Weekends does not allow a solution combined with Target Working Hours. That is weird -> Ask Johanna

Todos

• Get acurate Target Working Minutes per Employee. Who does work 50%, 30%?
• Does SOLL include the vacation days?
• free_shifts_and_vacation_days.json needs to be updated. Lets differentiate between different kinds of free days. Vacation Days, Blocked Days ("Does not work on Fridays"). Right now they are the same, which results in "No Night Shift before Vacation" if though they do not have a vacation.
• Look through "Free Weekends" and find out which hard constraints are set here. Ask Johanna, if it is possible that we cannot find a solution when we only add soft constraints? [Context: We find a solution with Target & Min Staff, but we dont find a solution when we add "Free Weekends"]

Target + Min Staff

[J0R0W]

Target Work + Min Staff + Free Weeksends: No Solution. This is surprising! Free Weekends should be a soft constraint, should not restrict the solution space

Johannas Answer:
Should be a bug. Soft constraints do not restrict the solution space

[Anas101101]

Regarding the Soll Times of the employees and the vacation days:
I already pushed a new version of the target_working_minutes.json, there is a new value called "actual" which represents the "Ist" Time that the employee already worked or the absences of the employee (so we pratically have the first "SOLL" and the second "IST" column from TimeOffice). If we now enter vacation days/other absences, it is not the SOll time that is changed, but the IST time (the shift time of the day is added to the IST time). To get the time that the employee is still allowed to work in the month we therefore have to subtract the IST from the SOLL time.
The current version of the target_working_minutes.json contains the right SOLL times and the right IST times excluding the Sondertatbestände and Wishes from the Problemstellung. You wrote above that would be handled in the code (free days of employees will be subtracted from target hour per employee), but if we have all the right IST times in here that would need to be changed (?).

Edit: As the Sondertatbestände/Wünsche don't change the needed working hours per employee ("Frei" is not the same as "Urlaub" or "Krank"), the target_working_minutes.json should be complete.