According to the Manual of Professional Practice for Quafity
in the Constructed Project, 2 "Quality Assurance (QA) is
a program covering activities necessary to provide quality
in the work to meet the project requirements. QA involves
establishing project related policies, procedures, standards,
training, guidelines, and system necessary to produce quality. The design professional and constructor are responsible
for developing an appropriate program for each
project. QA provides protection against quality problems
through early warnings of trouble ahead. Such early
warnings play an important role in the prevention of both
internal and external problems". On the other hand Quality
Control (QC) is the specific implementation of the QA
program and related activities. Effective QC reduces the
possiblity of changes, mistakes and omissions, which in
turn result in fewer conflicts and disputes