Evaluation of repair systems - Basic principles

When decision on repair has been taken the available repair systems/methods must be evaluated with regard to the immediate requirements. For each type and cause of damage, there are normally only a few possible repair systems. These repair systems should be evaluated with regard to following 5 basic properties, or characteristics: 1) service life/durability, 2) structural stability/safety, 3) execution of work, 4) environmental effects, 5) economy/cost. Besides, factors of non-technical nature, such as disturbances of different kind during repair work, might have to be considered in the evaluation. It is desirable that the evaluation leads to quantitative results. It has however been realised that a quantitative assessment often is impossible to make due to lack of knowledge regarding underlying physical phenomenon and material properties. Hence, three different levels of evaluation have been suggested: 1) "Approved solution", 2) "Qualitative evaluation" and 3) "Quantitative evaluation".