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The general objective of this research was to identify the practices of the mass production industries, on the decisions related to the detection of defective products and to identify relevant criteria, actions, effects and variables to be used in a decision-making model.

A survey questionnaire was developed and structured in 20 questions, with 18 closed questions and 2 open questions. The questions were constructed based on the literature review, with the identification of 15 theoretical and practical concepts of quality. Seven other information requests were included, concerning the initial characterization of the defective items and industry. The company, the product, the processes and the defects were contextualized, and then the decision-making process was framed, to understand the factors that influenced it.

The industries of the Industrial Pole of Manaus discard or rework their defective products influenced by promoting the lowest cost and the required quality. The factors with the biggest influence on decisions are rework and disposal costs, and time available for rework and replacement. The main requirements defined for the decision-making model were: 1) compare the rework and discard options, only if the rework reaches the required quality level; and 2) identify and account the effects of defective items on quality, productivity and costs.

Overall, 109 questionnaires were sent, representing 21.3% (109/512) of the companies at the Industrial Pole of Manaus. The respondents represent 14.6% (75/512) of the population.

Defects can occur, requiring a decision that promotes the lowest cost and the required quality. Quality cost models do not show a systematic analysis for identification, accounting, evaluation of effects and criteria associated with the destination of manufactured defective items. Therefore this research was done to fill this gap.

This paper proposes a decision support model that can be used to help decide the destination of defective products, for mass production industries. The objective of this model is to reduce the cost of the defect, and consequently reduce the total quality costs.

The decision model was developed based on the theory of quality costs and decision-making models, considering the practical aspects of reality through data collection, observation and experience in Industrial Pole of Manaus (Brazil) industries. A decision model adjusted to reality assists in the construction of the decision process, indicating the facts, data collection and the planning of the actions to choose the best alternative.

The specific contributions of this research are: (1) define a sequential structure of actions, effects and costs associated with defective items; (2) allow a comprehensive approach to failure costs, including various elements of lost opportunity costs; (3) minimize failure costs, and consequently reduce total quality costs, without necessarily investing in prevention and assessment; (4) describe the use and application of the built theory; (5) identify the quality cost elements most representative in existence of defective items; and (6) identify improvement points in the management of possible future defective items.

Much of the work of implementation of quality cost models do not emphasize the analysis of the destination of defective items. Also, there are no studies that use decision models with identification, accounting and evaluation of effects and criteria of quality, productivity and cost to define the destination of manufacture defective items.