A contractor may run a quality assurance (QA) system and some employers take this into consideration when making a list of selected contractors for tendering. QA is an administrative system for checking that the quality of a firms output complies with some set standards (see Reference 1). But this does not include a definition of the standards. For example a contractor may issue a design manual for formwork; this is his quality standard. His QA system then only stipulates the actions required to ensure conformity to such standards.
Such actions may include:
(a) designers must use the design manual;
(b) must have their designs checked by the firms formwork specialist;
(c) the specialist must check and sign the design as approved;
(d) the signed design sheets must be filed, indexed and kept;
(e) the agent or his site engineer must check and sign that the formwork is erected as designed;
(f) the contractors safety supervisor is to inspect and sign that the formwork erected is safe for use.
A QA system can cover a few or a whole range of a firms operations, but to ensure that it meets the intended objectives (which have to be defined) it has to be audited. Audits can be carried out internally by a member of the firm, or by a client proposing to employ the firm, or by an independent authorized certifying body who can issue a certificate of approval (see Reference 2). In the last case the QA system is said to be certified. Repeat auditing is required from time to time.
A supplier may say he runs a QA scheme to the current standard of ISO 9000, but this has nothing to do with the standards he adopts for his products which need not conform to any quality standard. Also a contractor can have a QA system but people may fail to follow it. A QA manager can be appointed to see the system is operated; but he will not know when checkers have signed without actually checking, nor may he know when checks have been missed.
On site a QA system can be difficult to run because most instructions will be given verbally, checks are visual, and much work is sub-contracted or done by temporary labour. Thus a QA system can exist, but it may not be effective.
A1994 report on seven major projects for the UK Concrete Society gave many instances of defects observed in concrete design and construction despite QA systems being run (see Reference 3).
A further difficulty is that the engineer must have the contractors QA system checked. This involves ensuring that (i) check procedures cover all necessary elements of work;
(ii) the procedures have a reasonable chance of providing the standards required;
(iii) auditing such procedures on an irregular and selective basis gives assurance they work effectively.
Setting up QA procedures and auditing are specialized activities and many companies have staff trained to carry out these tasks. A useful publication is see References 5 and 6). But under ICE conditions the engineer has a responsibility for ensuring the quality of the work is as specified and he cannot pass this duty to others. Even under ICE design and construct conditions and the ECC conditions the employers manager has powers, and therefore implied duties, to ensure work is satisfactory or defect-free. Such contracts would have to be radically re-worded if sole reliance were to be placed on a contractors QA system for quality of work done.
Only under some kind of turnkey or simple purchase contract might reliance be placed on a contractors QA system though, even with that type of contract, an employer may often appoint an inspector to watch over the contractors work on his behalf. The presence of a good inspector gives the employer, his engineer, and the contractor assurance that the work is inspected and is satisfactory.
His cost to the job may be no more than the increased price a contractor might charge for running and auditing a QA system and the cost to the employer of having to check the contractors QA system, and may give a better guarantee of satisfactory workmanship.
the ISO 9000 pocket guide (see Reference 4).
There has been extensive debate as to whether a contractors QA scheme could permit reduction of the engineers role in supervising the contract for construction; the idea being that the resident engineer would then only need to check that the contractors QA checking system was being properly applied.