Process control computers are finding ever increasing applications within the chemi- cal and mineral processing industries._x000D_
To purchase a system which fulfils both the immediate and future needs of operating, technical and management groups, requires an appreciation of the capabilities of the system software and the constraints which apply to user development of application software._x000D_
Early decisions are then required as to who will develop and maintain the software. Rules and conventions must be determined and adhered to if the end result is to be an orderly, well structured and properly documented system._x000D_
Software development and maintenance represents a substantial, and often hidden, cost. Getting it right the first time will avoid either a major re-work, or having to live with a system which is extremely diffi- cult (at the worst, impossible) to trouble- shoot or modify.