No consigo generar el horario completo

[Jose J.]

Buenas a todos,
He usado FET para hacer los horarios de mi centro los dos últimos cursos. Pero este año me está resultando imposible. Por mucho que modifico las restricciones o los condicionantes se queda a unas 20 actividades de alcanzar la generación total.
La cuestión es que no sé que debo corregir porque cada vez me aparece una actividad diferente la que genera conflicto. Además, al desactivar restricciones consigo resultados peores y no sé cómo arreglarlo.
¿Alguien podría ayudarme?

[ARROYIYO]

Buenas... Estoy en la misma situación y no sé como resolverlo...

[Volker Dirr]

It is easier if we can see your data file if you need help. In normal case just deactivate as much as possible until you understand the problem.

Or ask Liviu for a private video chat, but I suggest that only if you can pay him for such an extra work.

[ARROYIYO]

Buenas... Le paso el mío porque realmente estoy bloqueado... Mil gracias

[Volker Dirr]

It is impossible because you have too many activities with duration 2. That is impossible, since the are only 3 hours in the afternoon and FET can only place 1 activity with duration 2 per day in the afternoon.
So you have at least 2 variants to solve this:
a) Split the problematic activities into more parts with duration 1
or
b) make the break more flexible and allow for example break in hour 6 or 7.

[ARROYIYO]

Hello.

Thank you for your response. I really want a break during the 7th period, and I believe I've set a restriction so that no classes are taught during that time.

[Volker Dirr]

The restriction is below. You didn't use break contraint for that. You used students not available constraint. But the result is the same: You disallow hour 7. So in the afternoon are only 3 hours.
so you can count:
every group need at least 5 activities with duration 1.
And you must also count that all these 14*5 activities are teached by different teachers. A teacher is allowed to have max 5 activities with duration 1 if all other activities have duration 2 only.

[Volker Dirr]

Chat-GPT by the way told me the same. But i don't recommend his last suggestion. Chat-GPT suggested to use 95%. I suggest to use 100% and a) remove the 6th split activity from the min day constraint OR b) if you want it consecutive: set 0%, but add a second min day constraint with with 1st to 5th activity.

Quote from Chat-GPT:

I found a definite impossibility in the timetable. Activity **1066 is not itself incorrect**; it is simply where FET encounters the contradiction.

### The problem: M CAMACHO's workload cannot fit around period 7

| M CAMACHO activities        |          Quantity |       Duration |
| --------------------------- | ----------------: | -------------: |
| IDs 1052–1067 and 1071–1075 |                21 |     42 periods |
| IDs 1168–1170               |                 3 |      3 periods |
| **Total**                   | **24 activities** | **45 periods** |

Every student group is unavailable during period 7. Therefore, each day is divided into:

* Periods 1–6: 6 usable periods
* Periods 8–10: 3 usable periods

M CAMACHO has exactly 45 periods, so she must occupy every usable period. However, each three-period afternoon needs at least one duration-1 activity. Across five days, she therefore needs **at least five duration-1 activities**.

She has only **three**. Her other 42 periods consist of duration-2 activities, and an even-duration activity cannot fill an odd three-period block without a duration-1 activity. FET also cannot place a duration-2 activity across a break or unavailable period. [FET FAQ](https://lalescu.ro/liviu/fet/doc/en/faq.html)

### Recommended correction

Change one M CAMACHO duration-2 activity into two duration-1 subactivities, preserving the same weekly total. For example:

* French 5A, ID 1071: change `2` into `1 + 1`; or
* 4B Mathematics: change
  `2 + 2 + 2 + 2 + 2`
  into
  `2 + 2 + 2 + 2 + 1 + 1`.

Then M CAMACHO will have:

* 20 duration-2 activities = 40 periods
* 5 duration-1 activities = 5 periods

That pattern can fit the five three-period afternoons.

When recreating the split activity, use an appropriate "minimum 1 day" constraint between its components. FET normally adds this automatically; the 95% minimum-day component is soft and may be violated when necessary. [FET instructions](https://lalescu.ro/liviu/fet/doc/en/instructions.html)

The long "difficult activities" list is only the placement chain that led to the failure—it does not mean all those activities are erroneous. I also checked the other teachers with 45 periods: M CAMACHO is the only one with fewer than five duration-1 activities. The file itself is valid; the version difference is not the cause.