The objectives of this research are to propose a proper model for detecting defective machines in auto parts factories to apply the proposed model to the defective product data and to investigate the factors influencing on the machine producing defective products. A Bayesian hidden Markov model (HMM) is adopted. The results show that if the number of defective products increases the machine will be in the hidden bad state. The probability of changing from a hidden bad state to a hidden good state is higher than the probability of changing from a hidden good state to a hidden good state. The highest probability that the machine will be in a good state is at the work process 4 followed by 1 3 and 2 respectively. The highest probability that the machine will be in hidden good state is at the Worker no. 10 followed 9 3 12 7 2 1 6 11 4 8 and 5 respectively and The highest probability that the machine will be in the hidden good state is at the product type 1 followed by 2 and 3 respectively.

R & D PRECISION CO.LTD manufactures various types of work. Yet there were defects of work in previous working and the company was unable to deliver products to customers as required and some might have been destroyed. As the information referred to the waste detected each month from January 2014 to June 2014 it is found that the volume of defect rate was 9.56 percent resulting in losing cost of production and other business opportunities. This research aims to reduce waste in the production of high precision with lean concepts. The study starts from the analysis of employees working information by creating a value stream mapping. The study found that cylindrical grinding takes the longest time. Then the study explored and determined the root cause of the problem by using a Pareto Diagram together with a Fish-Bone Diagram to analyze the minor causes. It is found that most wastes are caused by measuring control especially for the work that has a shaft hole with thickness of 2.25 mm. Thus the study and experiment were conducted to determine the flow rate of the coolant for the work piece in the cylindrical grinding machine and a fixed value is the rate of decreasing the size of work speed of stone wheel and work type of coolant and type of grinding stones. The goal is to reduce waste by not less than five percent and to improve the process of reducing waste effectively which will affect the environment having lesser wastes from production. It also supports competitiveness and rapid change of industry manufacturing highprecision parts in the future even better.

The purposes of the study were to investigate Relationship between work environment and work satisfaction at Aurora Design Company Limited. 300 sample employees at Aurora Design Company Limited were selected to response to questionnaire. Computer package software was applied to acquire the values of percentage distribution mean standard deviation and Pearson Correlation Coefficient. It was found that in the aspects of welfare colleagues work security work promotion working hours income wage were significantly related to work satisfaction. In terms of satisfaction on work position advancement and job description perception were interconnected to work satisfaction.

The purposes of the study were to investigate the organizational commitment compare factors affecting the organizational commitment and explore related factors affecting the organizational commitment of the personnel working at Suan Dusit University the questionnaire was administered to 362 samples and analyzed by the percentage distribution mean - Way ANOVA and pearson product moment correlation coefficient analysis set at 0.05 statistical significance. The study results revealed that Suan Dusit University personnel had high level of organizational commitment in general. Factors related to overall working performance were good and working experience was in average. It is also found that the organizational commitment level of the personnel who were different in different in terms of age marital status educational level work tenure and salary Income at 0.05 statistical significance. Additionally overall working performance as well as working experience was highly and positively related to the organizational commitment in general.

The purposes of the study were to 1) investigate opinions towards the personnel development activity model 2) explore opinions towards the personnel development and 3) examine the personnel development activity model towards Bangkok Central Crown Property Bureau personnel capacity development. The samples of the study were 330 employees working at Bangkok Central Crown Property Bureau selected by proportional stratified random sampling. The data collected were analyzed by the percentage distribution mean and standard deviation; and t-test F-test and multiple regression analysis resulted at 0.05 statistical significance. The results revealed that most of the samples were single females ranging from 31 to 40 years of age holding bachelor degrees. Their average income salaries were 20001 to 30000 Baht. They were working in practical and administrative operational positions and had been working for five to ten years. In general most of the participants reflected that the personnel development activity model which included administrative activities training activities professional planning activities and teamwork activities had high impact on the personnel capacity development. It was also found that personal factors concerning differences on the employee’ age education status tenure range position resulted in different capacity development outcome. In addition most of the participants revealed that the personnel development activity model which included administrative activities training activities professional planning activities and teamwork activities had influence on the personnel capacity development.