Reliability is the Future

History and Development of Reliability Engineering

From a state-owned enterprise to a foreign company, from an equipment engineer to Senior Reliability Manager, Alex Chen has developed a deep understanding of equipment maintenance and reliability in chemical industry in his career. Starting with ‘breakdown maintenance’ at the first stage, followed by ‘preventive maintenance’, and then ‘reliability centered maintenance’ became popular as well. Each area aims for the perfect balance of minimized resources for maintenance and a suitable level of reliability, to ensure satisfaction of requirements for the equipment.

What is reliability? Reliability is the probability that an item can perform its intended function for a specified interval under stated condition. Generally speaking, reliability is all about durable service. No matter if the application is for aviation or a home appliance, reliability is closely linked to industry and our daily lives. Yet different industries have different focuses for reliability management. For example, the process industry is quite different from the discrete industry in terms of reliability, but it is clear that building a ‘reliability-centered culture’ is essential to the development of companies and industries today.

“The concept of reliability was initiated in the 1930s and 1940s,” explained Alex: “It was initially used in the military field in the western world. In 1950s, Americans published the ‘Reliability of Military Electronic Equipment’ as a guideline document. It was a milestone that defined the direction for the development of reliability engineering. It also reiterated that reliability engineering had be-come a new independent discipline. In the 1960s, reliability engineering evolved to include a full range of applications, extending from the military to civil works. In the 1970s, the concept of reliability engineering spread from a limited number of countries to all over the world.

Many more countries soon began to research on and adopt practices for reliable engineering. This is a constant, ongoing progress that matures with industries and steadily grows in influence.

With the ever-changing complexity of modern industrial processes, and severity of process conditions, industries are more demanding of equipment and its reliability. Alex analyzed the course of change in the managing principles of equipment reliability. “According to the development history of equipment maintenance concept, the earliest approach was ‘breakdown repair’. At that time, equipment was relatively simple and was not expected to deliver outstanding performance. In the 1940s and 1950s, equipment breakdown imposed a greater influence on production. That gave birth to the concept of ‘preventive maintenance’. In the 1960s and 1970s, ‘predictive maintenance’ became more and more popular. By analyzing early fault signal purposely collected, maintenance could be performed preventatively with proper planning. That helped to eliminate both excessive maintenance and insufficient maintenance. After that, the concept of ‘reliability-centered maintenance’ came up. This helps to formulate maintenance strategy based on logical decision making.” Other reliability tools have been developed in recent years as well, such as FMEA (Failure Model and Effect Analysis), DFR (Design for Reliability), RCA (Root Cause Analysis), etc.

Alex Chen, Dow Chemical, end user. engineer

Key to Improving Reliability: the ‘Full-life-cycle reliability concept’

Alex always conducts equipment maintenance at customer facilities. In the earlier stages, he focused on routine management, such as scheduled inspection, maintenance, spare part management, overhaul planning and coordinating. Later, his focus changed to reliability data analy-sis, equipment maintenance strategy, and root cause investigation on unplanned failures. Years of work experience with equipment makes him certain about one concept — the inherent reliability of any equipment should always be decided early in the development and design stage. “In the stage of equipment operation and maintenance, the objective is more about maintaining the reliability of the equipment.”

Therefore, it is necessary to bear in mind the ‘full-life-cycle reliabili-ty concept’ all the way through the planning, designing, manufacturing, operation, maintenance and write off. “Link the pools of data from each equipment stage and connect them into a closed loop. That is the most effective way to help improve the reliability of equipment, gathering relevant information into one place.”

Alex mentioned there is specific terminology, such as inherent availability, achieved availability, and actual availability, tied to reliability. Inherent availability is determined by the product design, although sometimes it will be partially compromised during manufacturing for various reasons. A finished product exhibits the achieved availability when the product reaches the end user and is put into service, but its reliability will be compromised during operation and maintenance. What an end user is most experienced with is the actual availability. Alex related product reliability to a human life span. In simple terms, a human’s maximum life span is determined by genes. However, the inherent life span will be compromised during pregnancy. After birth, the life span will be further compromised due to living habits, medical conditions, health management, etc. That is why they live within this actual life span. The more attention is given to reliability in the planning and design stage, the more potential to improve the product re-liability in the long term. In another words, it will be more difficult and expensive to improve reliability in a later stage than in an earlier stage.

“In the specific case of equipment operation and maintenance, take valve as example, when a critical valve goes wrong, we will firstly carry out root cause analysis. Com-mon causes include design deficiency, incorrect use, improper maintenance, etc. Then we will feed back the related design information to the manufacturer in question. Then manufacturer can improve their de-sign according to our feedback and hence improve the inherent reliability of their product. In fact, series of reliability tests will be done during the design and manufacture stage. When the test data so acquired is jointly used with user’s application data, better effect on boosting the product reliability can be expected,” Alex gave us such an example.

Reliability Engineering boosts Manufacturing Industry

Working to improve reliability engineering, Alex naturally feels a sense of responsibility. He is convinced that with the development of modern industrial technology, the role reliability engineering plays is be-coming more and more important.

It is necessary to share knowledge and experience about reliability to strengthen the community and build better reliability technology. “Quality and reliability are inseparable. Broadly, reliability is a key part of quality. In a narrow sense, reliability means quality over time. Tradition-al quality concepts are more about the satisfaction of quality criteria prior to and upon leaving the facto-ry (t ≤ 0, ‘t’ refers to the time line of product life cycle. t = 0 refers to the moment when product hits the shelf.). Reliability engineering cares more about the failure that occurs after the product hits the shelf (t > 0). People have only been able to judge product quality using provided technical parameters as a reference for many years. Unfortunately, this only reflects quality from one single perspective. If the product is not reliable, none of the technical advantages can be realized in service. In a sense, reliability is a comprehensive index about product quality. It is necessary to build up a modern understanding of quality, broaden the meaning of quality reliability, improve price efficiency, safety, reliability, maintainability, and support performance. For the same reason, time spent on quality management should be extended – from development and design all the way to the end uses application.”

Alex hopes that domestic companies start to build the reliability culture and invest more resources in reli-ability engineering. He explained: “With the progress of localization, competition between domestic and imported equipment is going more and more fierce. As an end user, we care not only about the initial price – but we also care about reliability and life cycle cost. This suggests that manufacturers should address reliability issues in each stage of a product lifecycle. Customers’ needs can be satisfied using a better approach. The importance of quality and reliability surely outweighs that of price advantage, because outstanding quality and reliability is the inevitable path towards core competence and brand promotion.”

After years of cultivation in the field of reliability in chemical industry, Alex realized that outside his daily routine, he can contribute more by sharing his understanding and experience about reliability with young generation engineers, specifically promote the culture, thoughts, and knowledge about reliability. Alex looks forward to sharing his experience with attendees as the 2021 Valve World Asia Conference Chairman, to be hosted December 6-7, at the Shanghai New International Expo Center.

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