A very high degree of refinement of loss estimation is neither desirable nor warranted, because of the multiplicity of factors affecting the estimate. Consequently, lump-sum estimates of losses are more realistic. Particularly in routine design and under average conditions. Such lump-sum losses can be summarized in Table 3.1 of AASHTO and T able 3.2 of PTI. They include elastic shortening relaxation in the prestressing steel, creep, and shrinkage, and they are applicable only to routine, standard conditions of loading, normal concrete , quality control, construction procedures, and environmental conditions, and the importance and magnitude of the system. Detailed analysis has to be performed if these standard conditions are not fulfilled.