A process which has built-in reliability is one which permits large tolerances in processing without failing. In this way it is possible to differentiate various products according to their "built-in reliability". Benchmarking is a successful procedure for assessing different products. With the 2-component products for coatings, for example, PUR does not react to quantity errors as sensitively as EP. Nor is dependence on temperature as high. What is more, PUR can have a certain resilience which can help to bridge cracks. For this reason it is a more reliable material than EP indoors.

For outdoor applications, where moisture, including temperatures below the dew point, plays a major role, EP is more suitable, although, for reliability reasons, the surface should be as dry as possible and the temperature should never fall below the dewpoint.

If a material reacts sensitively to porosity in the existing surface (with PMMA polymerization will then be inhibited by oxygen), a less sensitive material than PUR should be used.

Physiology can also exert an influence: that is why on construction sites UP, which contains styrene, is replaced by EP.

If a fibreglass reinforcement is to be used for a "self-supporting" coating, the only choice is EP.

In the "Benchmarking" procedure impregnation can be characterized according to 33 properties. These properties in their entirety can be achieved by adding 30% solvent. Solvent-free systems are less (foolproof) and there has to be a compromise between the environment and safety at work. Formulas which are resistent to ultraviolet light are more expensive. In many cases no cost-benefit analysis has been performed.

However, one must be careful in generalizing according to the 4 groups of materials PUR, EP, PMMA and UP. Inherently they are all extremely heterogenous and can be "blended" with one another. Composite methods of construction are possible and customary in acid protection and concrete protection.

It would be possible to state an index of "foolproofness" for each process if one asks 100 average placement contractors to test the same procedure and assesses in each case to what extent each contractor copes with the material.