Quality costs more, lack costs even more

Quality

Quality is the degree to which the project deliverable satisfies the specified requirements and the needs of the client; in simple words, "fitness for use" or "conformance to requirements".

Quality costs more, but lack of quality costs even more

Good quality needs money for planning, training, better materials, inspection and testing. But poor quality is far more expensive: rework, rejection, delay, repair, claims, loss of goodwill and, in construction, structural failure and loss of life. The total cost of quality is:

$$\text{Total quality cost} = \text{Prevention} + \text{Appraisal} + \text{Internal failure} + \text{External failure}$$

Illustration (Rs thousand, for one slab-casting package):

As spending on prevention and appraisal increases, the failure cost at first falls much faster, so the total cost falls until it reaches an optimum (Rs 50 thousand here); beyond that point, extra spending saves less than it costs. For example, spending Rs 20,000 on testing and supervision of a slab can avoid demolition and recasting costing lakhs. Hence the statement is justified: the cost of a lack of quality (failure costs) is greater than the cost of achieving quality.