It depends entirely on the context. For example, you could write

The technicians were fired to reduce the company's costs.

but

1. "The company" is not really the subject of the infinitive. The possessive is an adjective modifying "costs"
2. The passive tense already implies the subject is whoever employs the technicians. It's not necessary to explicitly repeat this to relate it to costs.
3. It's fairly obvious that it's the employers who are going to save money by being fired, not the technicians.

You would have to add specifics if it is not clear what the infinitive clause modifies. For example:

The technicians were promoted to improve productivity.

Although this sentence is grammatical, it's not clear whose productivity is improved. The technicians? The company overall? The executives who make these kind of decisions? Better to be clear:

The technicians were promoted to improve company productivity.

It depends entirely on the context. For example, you could write

The technicians were fired to reduce the company's costs.

but

1. "The company" is not really the subject of the infinitive. The possessive is an adjective modifying "costs"
2. The passive tense already implies the subject is whoever employs the technicians. It's not necessary to explicitly repeat this to relate it to costs.
3. It's fairly obvious that it's the employers who are going to save money from this action, not the technicians.

You would have to add specifics if it is not clear what the infinitive clause modifies. For example:

The technicians were promoted to improve productivity.

Although this sentence is grammatical, it's not clear whose productivity is improved. The technicians? The company overall? The executives who make these kind of decisions? Better to be clear:

The technicians were promoted to improve company productivity.