This Guide provides interpretations and advice on the application of quality assurance to the construction industry, and gives additional recommendations and guidance on specifying and developing effective quality systems for construction projects and organizations.The Standards provide models for 'quality assurance', i.e. they deal with those elements of quality systems which give the customer confidence that the supplier will deliver what the customer wants; the scope of this Guide is therefore similar.The three models provided by the Standards are as follows:AS/NZS ISO 9001 Quality systems -Model for quality assurance in design, development, production, installation and servicingContains 20 requirements clauses which cover the full process of developing a project (or part of a project) from design through to servicing. Section 4 of this Guide provides interpretations and guidance against each of the 20 elements.AS/NZS ISO 9002 Quality systems - Model for quality assurance in production, installation and servicingIdentical with AS/NZS ISO 9001, except that requirements for Design control (Clause 4.4) are excluded.AS/NZS ISO 9003 Quality systems - Model for quality assurance in final inspection and testContains 16 requirements clauses for use where quality assurance is based on verification of conformance to specified requirements prior to delivery or handover, i.e. 'final inspection and test'. The clause numbers and titles are the same as those in AS/NZS ISO 9001 and 9002, however some requirements are less extensive, and there are no requirements for Design control (Clause 4.4), Purchasing (Clause 4.6), Process control (Clause 4.9) or Servicing (Clause 4.19). Users need to be aware of these differences in applying the guidance provided, particularly in Section 4.Common applications for the Standards in the construction industry are-(a) for specifying a quality system for a project or part of a project; and(b) as the basis of certification of a supplier's quality management capability, i.e. third-party or second-party certification.The recommendations and interpretations provided in this document recognize both these uses of the Standards.The construction industry involves a wide diversity of participants and of products. The scope of a quality system will vary from situation to situation; for example, it may be influenced by programmes and schedules, the customer's concerns, previous experience, the critical importance of the goods or services, and safety requirements. This Guide recognizes that the diversity of the applications to which it will be put limits the degree of details possible and extrapolation and common sense on the part of the user is required when applying the requirements of the Standards and the recommendations of this Guide to particular situations.This Guide applies to all forms of construction projects, which typically involve both on-site construction and off-site manufacture, as illustrated in Figure 1.1.