Managing Reliability the DMSICOM Cycle
Design
The inherent reliability of an item is set during the design phase. Techniques such as design for reliability, design for maintainability and design for purpose are used to create a system that is reliable enough to meet the anticipated needs of the business. Everything that happens after the design phase removes a little bit of the inherent reliability. It is our job to ensure that steps are taken during each subsequent stages to maintain as much of that inherent reliability as is needed for the business to be successful. There is no amount of operating discipline and maintenance activity that can increase the inherent reliability of the item.
Manufacture
The manufacturing process removes some of the designed in reliability due to variation in manufacturing methods. Creating items with wide tolerance windows can result in items that have widely varying levels of reliability. Tolerance stacking can lead to either fits that are too tight or too loose. Equipment specifications must include items such as maximum acceptable vibration levels, etc. as quality control measures to ensure the manufactured item will be reliable.
Ship
The impact of shipping is often overlooked as a source of unreliability. It is important to include shipping specifications when purchasing equipment to ensure that it arrives in the best possible condition.
Install
Poor installation practices often lead to infant failures in newly built systems. It is important to build a quality management program into the project in order to ensure the best possible installation that maintains as much of the inherent reliability as possible. There need to be quality assurance steps built into the installation procedures, and quality control measure taken after installation. It is important to ensure that items of equipment are well protected upon receipt, and that they are installed as soon as is practical. I have seen the results of equipment stored outdoors without proper protective measures, and they are usually ugly.
Commission
Strong commissioning procedures are very important. Many items of equipment have been damaged by improper startup due to lack of good procedures. Some things I have observed are conveyors being lifted off the floor by using the wrong type of crane to remove sheet metal from the conveyor, fume incinerator tube bundles destroyed because ramp and soak cycles weren’t set up properly for startup and pumps damaged due to being started up dry.
Operate
Equipment must be operated within the ranges that were anticipated during the design phase. Reliability will be high provided that the designers fully understood the operating requirements.
Maintain
A minimally invasive maintenance strategy is only one aspect of maintaining the item or system. Ensuring high quality when maintenance work is accomplished is likely more important than the actual maintenance strategy. A quality management program that ensures all rebuilds, installations, repairs and lubrication actions are done to exacting standards will help ensure high reliability.
Nice article Bill. Design defines the genetic code for the reliability of the asset. As asset management and reliability engineers, we need to work harder to influence design for reliability, maintainability, operability and all the other functional “abilities” we require from the asset.
Sir would you like to add debottleneck after maintain to include proactive design out of failure components with technology improvements .
A factory acceptance test (FAT) should also be completed to ensure specifications are met prior to equipment shipment. Also a site acceptance test (SAT) needs to be part of any commissioning program. FATs and SATs will help insure inherent reliability.
Another acronym.....Why not. Just have to figure out how to pronounce it :-). Great read Bill. As always spot on and to the point.