The process controls mainly pertain to the activities which are required to be carried out at any particular stage of the process. Often the final product will comprise of a number of components and assemblies some of which may be purchased items the satisfactory quality of the end product quality control should cover the various stages of manufacture of an components and assemblies which are processed in the plant. In addition if should also cover the quality assurance of all incoming materials and components. This will require a network of control stations located at strategic points in the plant. At each control stations the quality characteristics to be controlled should be clearly defined and adequate test equipment and trained staff should be provided to carry out this functions.