To explore this point further in Civil Law or Common Law
In Civil Law countries, particularly France, by default, the Service Provider is held to a best-efforts obligation: the service provider must use all reasonable efforts to achieve the expected result. Exception: express performance obligation clause.
In case of breach, liability arises upon proof of failure in the means employed and a fault attributable to the service provider.
Damages are intended to compensate for the actual loss suffered by the client, modulated by the distinction between a best-efforts obligation and a performance obligation (see Articles 1104 and 1231-1 of the Civil Code).
The service provider must demonstrate that it has taken reasonable steps to achieve the objective, but is not necessarily required to guarantee.
COMMON LAW "Fit for purpose" obligation: the service provider guarantees that the service or product will be suitable for the use defined by the client.
The client will have to show that the service was not "fit for purpose", i.e. that it did not meet the use for which it was intended.
Damages are awarded based on the loss resulting from the inability of the service to be adapted to its intended use, often calculated more strictly.
To go further with examples of FIDIC white book clauses: clauses 3.1 to 3.3
3.1.1 The Consultant shall perform the Services as stated in Appendix 1 [Scope of Services].
3.1.3 The Consultant shall perform the Services in accordance with the Programme as may be amended from time to time in accordance with the Agreemen
The Consultant declares that as at the date of signature of the Agreement there are no circumstances or matters that may give rise to a conflict of interest in the performance of its obligations under the Agreement. The Consultant shall inform the Client immediately if it becomes aware of any such circumstances or matters. If a conflict of interest arises then the Parties shall agree, in good faith, on measures to manage such conflict.
3.2 Function and Purpose of Services 3.2.1 Where appropriate, the Client shall describe the function and purpose of the Services and state the same explicitly in Appendix 1 [Scope of Services].
3.3 Standard of Care 3.3.1 Notwithstanding any term or condition to the contrary in the Agreement or any related document or any legal requirement of the Country or any other relevant jurisdiction (including, for the avoidance of doubt, the jurisdiction of the place of establishment of the Consultant), in the performance of the Services the Consultant shall have no other responsibility than to exercise the reasonable skill, care and diligence to be expected from a consultant experienced in the provision of such services for projects of similar size, nature and complexity.
3.3.4 To the extent achievable using the standard of care in Sub-Clause 3.3.1, and without extending the obligation of the Consultant beyond that required under Sub-Clause 3.3.1, the Consultant shall perform the Services with a view to satisfying any function and purpose that may be described in Appendix 1 [Scope of Services].
3.3.5 The Consultant shall comply with all regulations, statutes, ordinances and other forms of standards, codes of practice and legislation applicable to the Services and the Agreement.