This paper discussed an integrating manufacturing execution system in pressure vessel industry. MES optimizations (MESO) is a reliability growth process which is applicable to manufacturing firms to unify the supply chain plan, the service and the production automation, transferring the company's service goal to the definite operation goal and realizing the multi-varieties, multi-batch, high quality and low-cost of the production demand. This system is a complex operating system which is composed of certain subsystems, and it could complete the specified function. Basing on the MES functional module, this paper has investigated on the enterprise productive plan and scheduling module to realise the reliability growth and product quality improvement as well as some key technical strategies. Combined with the quantitative evaluation and analysis method of the reliability engineering, the paper also made an analysis for the numerous resources entity and functional module of the overall system and formed a research subject on the theory relative to the reliability growth of the MES. The research on the case has a certain instruction function for the enterprise which is going to put the MES into effect.