1. According to the principle of efficiency, tort liability principles ought to minimize the accidents costs including the prevention cost, the accident loss, as well as the administrative costs.

2. However, these traditional quality cost analysis model almost focused on quality cost, thinking that the prevention cost increased with the quality improvement, and the failure cost decreased.

3. Quality cost is the cost which is needed to keep product quality at the given level, it includes prevention cost, appraisal cost, internal losing cost and external losing cost.

4. In optimum prevention framework, the optimum prevention level for government regulation is at the point that marginal prevention cost is equal to expected marginal accident cost.

5. From the point of view of efficiency, the optimum prevention level for one community and government regulation is that the marginal prevention cost is equal to the marginal anticipated accident cost.