To develop a maximum of aesthetic and structural performance, the architect, engineer, building official, contractor and producer must comprise a team. Unfortunately, recent developments have not all been in a positive direction. Hassles over concrete quality still too often lead to costly repair, replacement, or refusal of payment, and unfailingly detract from the reputation of concrete as a building material. Therefore it is necessary to spell out the responsibilities of all the parties involved. The architect and engineer's job is to specify the quality of the materials. Failure to do this will only cause heartaches later on. It is common for a building specification to state that concrete furnished for the work shall have the compressive strength shown on the plans- with no description of testing, limits on the frequency of sampling, basis for interpreting tests, or statement of the consequences of low measured results. Therefore sampling and testing are likely to be non-standard, with no recognition in the specification of the inevitable variation in test results, and with no basis established for disputes, trouble is almost inevitable. Another potential problem is between contractor and producer. The contractor is looking for the cheapest price so he can submit a low bid; the producer has to try to offer the lowest price even if he thinks the specifications are shady, or the contractor will go elsewhere. The solution is found in education- of the contractor to the fact that more than price is involved in selecting a source of concrete, and of the producer to the necessity for understanding requirement s and knowing ahead of time that he can meet them while also meeting payroll.