The sea bed is not the most accessible of places for dealing with breakdowns or the retrieval and replacement of defective equipment, nor does it permit frequent and easy maintenance operations.

Subsea installations are therefore designed for long trouble-free periods of operation of many years' duration The necessity for quality assurance when purchasing equipment is very obvious.

The purpose of this chapter is to give an insight into the setting up and operation of quality assurance and control activities relevant to the provision of equipment for subsea installations Additionally, some examples are given based on experiences during the last 3 years, of incidents which demonstrate the need for precise communication of quality requirements and the value of dedicated surveillance during manufacture and testing.

Quality assurance and quality control are not the same, and an appreciation of the difference is necessary. In the past there has been a considerable degree of misunderstanding, and it was proclaimed by some sceptics that both of these were merely fancy new names for inspection - and an excuse for delaying progress of work by introducing requirements for vast quantities of documentation and certification to satisfy the whims of customers and regulating authorities.

No doubt the objectives of a quality system as being the identification and specification of relevant "good engineering practice" with subsequent confirmation by monitoring, recording and certification are better understood throughout industry today than several years ago, and also the difference of meaning between "assurance" and "control", but never-the-less it might be prudent to commence by defining these terms again, and by briefly summarizing quality assurance philosophies and the formal quality system which results in the establishment of a quality plan setting out the degree of control which must be exercised


Quality assurance is the systematic performance of all planned activities and functions necessary to provide confidence that an item or facility will be satisfactory in service.

Quality control consists of those actions which provide a means to control and measure the characteristics of an item or facility to specified requirements

Most companies now profess the philosophy of operating a quality system in accordance with BS 5750 or similar standard, to whatever degree is suitable for their activities and product. This philosophy will recognize that the assurance of quality must be fundamental for all work carried out within the organization, and must be practised by all personnel in their dally activities The existence of a QA/QC department within the organization does not diminish the individual quality related responsibilities of other personnel

The philosophy will also recognize that quality is enhanced by working in a disciplined manner to formal procedures designed to eliminate the occurrence of deficiencies, and that the evidence of quality, before the self-evidence of satisfactory performance in service, is provided by records generated during any activity undertaken towards provision of the product

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