The service provider has to respect the service contract they made with you. But does the service provider have to achieve a specific result or merely do their best? It all depends on the type of work the provider was hired to do and the circumstances they had to face.
Guaranteeing the final product: obligation of result
In some situations, the service provider is required to achieve the final result specified in the contract. They are then said to have an “obligation of result.” This is normally the case when the result cannot be influenced by chance or by events beyond the control of your service provider.
For example, a computer specialist must install software correctly. In this type of situation, the service provider will be held liable if they do not deliver the expected result.
Only a case of superior force could release the service provider from the obligation to deliver this result. For example, a power failure could prevent your IT specialist from completing their work, through no fault of their own.
Taking reasonable means: obligation of means
In other situations, a service provider must use all reasonable means to achieve the expected result, but the end result remains beyond their control. They are then said to have an “obligation of means.”
For example, a lawyer representing a client must use all reasonable means to try to win the case, but does not have to guarantee victory. Similarly, if your dentist performs an operation on you, they must use all reasonable means available to them to ensure that it is a success.
Different obligations for the same service provider
Both of these types of obligations may apply in the same contract.
For example, denturists must guarantee results in terms of the comfort and convenience of dentures (pain and difficulty chewing). This is an obligation of result.
By contrast, they must use all reasonable means when it comes to making the dentures (quality, strength of materials, ensuring that the finished product matches the imprint, etc.). This is an obligation of means.