Final answer:
Top management support is necessary when implementing a complete quality cost system, as it ensures resource allocation, seriousness, and a reinforced quality culture company-wide. Option 3 is correct.
Step-by-step explanation:
When implementing a complete quality cost system, certain aspects are fundamental for its success. Among the given options, top management support is crucial. Management's support is necessary to ensure that resources are allocated, the program is taken seriously throughout the company, and that a culture of quality is reinforced at all levels of the organization.
While broad categorization of cost data can be useful, and the quality department will play a significant role, it is the leadership's endorsement that drives the effectiveness and cohesion of quality initiatives. Additionally, although a company-wide simultaneous implementation may seem ideal, it's not strictly necessary for establishing a robust quality cost system.
Hence, the correct option is 3.