The role of the user in achieving reliability

Abstract

It has been more than adequately demonstrated that the distribution of load is far more influential on the reliability that is achieved by an item than is the distribution of its strength. The reader could well refer back to sections 4.1 and 4.5 for confirmation. Nothing dismays the author more than to become involved in an argument between a designer or manufacturer and a user regarding the responsibility for reliability: often a futile exercise in blaming the other guy without regard to realities. Abuse can clearly cause failure. While there may be some circumstances when intentional abuse is justified, these are essentially cases of calculated risks and outside the scope of this book. Unintentional abuse is a real cause of failure. There is only one remedy, and that is adequate training of the operator. The operator must be fully aware of the limitations designed into the equipment and the conditions of use for which it was intended. However, these should be agreed between designer and user. Only too often what is abuse to a designer is common practice to the user. The user and designer must come to terms. How this is to be achieved will obviously depend on the circumstances. If the purchaser is calling for a special product to meet his needs, he has a duty to define, in its specification, the exact conditions under which he intends to operate the equipment. Furthermore, he has a duty to see that the equipment is subsequently operated within those conditions, though perhaps less of a duty than an act of self-interest. Success in this connection is primarily achieved by adequate operator training and rigorous discipline. It is amazing how much money and effort is put into conventional quality control, which is control of the product, and how little into operator quality control. Very real gains are available to those who invest in a sound operator training programme and back it up with an assessment of actual usage. Some hostile environments and some adverse conditions cannot be avoided. These should be specified so that the design makes due allowance for them, or the possibility of failure is accepted. Otherwise reliability is in the hands of the user.