Time, Cost, and Quality are triple constraints or three primary objectives that a project manager must balance in carrying out a project.
What is quality? There are many definitions. The Institute of Quality Assurance (2002) says this about quality:
In its broadest sense, quality is a degree of excellence. It is the extent to which something is fit for its intended purpose.
In the narrow sense, product or service quality is defined as conformance with requirements, freedom from defects, or simply a degree of customer satisfaction.
The American Society of Civil Engineers (ASCE), in its much-lauded Quality in the Constructed Project: A Guide for Owners, Designers and Constructors (American Society of Civil Engineers, 2000) defines quality as;
‘the fulfillment of project responsibilities in the delivery of products and services in a manner that meets or exceeds the stated requirements and expectations of the owner, design professional, and constructor’.
OR “contractor’s task in managing quality is to assure compliance with the technical requirements of the project, as described in the contract documents, through a series of steps that plan, execute, monitor and control the physical aspects of the work”.
Quality Assurance and Quality Control
Although these terms are sometimes used synonymously, it is helpful to distinguish between them.
Quality assurance may be defined as ‘planned and systematic actions focused on providing the members of the project team with confidence that components are designed and constructed in accordance with applicable standards and as specified by contract.’
Quality control, on the other hand, is ‘the examination of services provided and completed work, together with management and documentation practices, that are geared to ensure that project services and work meet contractual requirements’ (American Society of Civil Engineers, 2000).
Thus a contractor’s quality assurance programme includes all activities that ‘assure quality’ includes the selection of subcontractors, training of the workforce, use of proper methodology, and the various testing activities.
Quality control is one part of quality assurance.
One means of attempting to reduce construction quality problems and assuring quality performance by construction contractors is certification by the International Organization for Standardization. That organization uses the designation ISO to refer to all of its standards, the term is derived from the Greek isos, meaning equal; thus its standards apply equally or universally for a given situation or condition.
The ISO standards related to quality are known as the ISO 9000 series of standards. The ISO 9001 standards are for organizations that design, produce, install, and service products, while the ISO 9002 standards apply to organizations that only produce, install, and service products. The standards apply to all kinds of organizations. In the area of construction, ISO 9002 certification is sought by contractors who do not perform design services, while design-build contractors fall under the ISO 9001 guidelines.
Many owner organizations require their contractors to be ISO-certified or to meet similar standards.
The following elements are appropriate for the quality assurance/quality control programme:
- Recruiting and assigning a skilled workforce
- Quality control organization
- Project progress schedule
- Submittal schedule
- Inspections
- Quality control testing plan
- Documentation of quality control activities
- Procedures for corrective action when quality control and/or acceptance criteria are not met.
During the project operation phase, the contractor is usually required by the contract to furnish and abide by a quality plan.
COST OF QUALITY
Quality costs are broken down into two categories: the cost of prevention and appraisal and the cost of failure.
The breakdown of these costs is shown below:
Quality costs = Control costs + Failure costs
Control costs = Prevention costs + Appraisal costs
Failure costs = Internal failure costs + External failure costs
In terms of construction, the prevention costs are the costs resulting from quality activities employed to avoid deviations.
The appraisal costs consist of costs incurred from quality activities employed to determine whether a product, process, or service conforms to established requirements.
The failure costs are the costs resulting from not meeting the requirements. Internal failure costs are the costs incurred on the project site due to scrap, rework, failure analysis, re-inspection, supplier error, or price reduction due to non-conformance. External failure costs are costs that are incurred once the project is in the hands of the client. These include costs for adjustments of complaints, repairs, handling, and replacement of rejected material, workmanship, correction of errors, and litigation costs.