In software quality management, what are the main parameters or categories that are typically included when calculating the overall cost of quality (quality cost) for a project?

Introduction / Context:
In software engineering, the phrase "cost of quality" or "quality cost" refers to all the money and effort that an organization spends to prevent defects, to find defects and to deal with defects that escape into later stages or production. Understanding the parameters of quality cost helps managers justify investments in testing, reviews and process improvement because they can clearly see how prevention and appraisal reduce expensive failure costs.

Given Data / Assumptions:

We are talking about cost of quality in the context of software projects, not manufacturing alone.
The industry standard model divides quality cost into clear categories rather than mixing it with general project expenses.
The question asks specifically for the main parameters or categories, not individual examples of activities.

Concept / Approach:
The widely accepted model breaks the cost of quality into four categories. Prevention costs are incurred to avoid defects in the first place, for example through training, standards and process improvement. Appraisal costs are spent to assess the product, such as reviews, inspections and testing. Internal failure costs are the costs of defects found before release, including rework and retesting. External failure costs arise when defects reach customers, such as support calls, hot fixes, penalties and loss of reputation. Together, these four categories describe how quality related money is spent.

Step-by-Step Solution:
Recall the standard breakdown of quality cost: prevention, appraisal, internal failure and external failure. Check which option lists exactly these categories without mixing in unrelated project costs. Option a clearly mentions prevention, appraisal, internal failure and external failure costs. Option b mixes general lifecycle stages like development and marketing, which are broader than quality activities. Option c and option d focus on financial accounting lines or project management constraints, not specific quality cost categories.

Verification / Alternative check:
If you open any standard software quality assurance or project quality management textbook, the cost of quality model is defined by these four categories. Organizations often measure and report them to show how increased prevention and appraisal can reduce failure costs over time. This confirms that option a matches the accepted terminology and structure.

Why Other Options Are Wrong:
Option b describes high level project spending areas, but does not distinguish between quality focused costs and normal development work.
Option c lists generic expense categories such as hardware and salaries, which are important but not specific to quality activities.
Option d mentions schedule, scope, budget and risk, which are classic project management constraints, not quality cost parameters.

Common Pitfalls:
Many people confuse total project cost with cost of quality and assume that any project spending is a quality cost. Another mistake is to think quality cost is only testing cost, ignoring prevention and appraisal activities. Remember that the real power of the model is in comparing prevention and appraisal versus internal and external failure to balance investment in making quality versus paying for poor quality.

Final Answer:
The main parameters of cost of quality are prevention costs, appraisal costs, internal failure costs and external failure costs.