Remove Failure Causes And You Guarantee Reliability Improvement And New Operating Profits That Last Forevermore

Do You Want To Improve Your Plant And Equipment Reliability And Make More Operating Profit? Then Proactively Remove Its Failure Causes!

Deliberately create equipment reliability by purposely removing the chance of its components failing. Without a cause of failure there can be no failure.

Slide 17 – Improve Equipment Reliability = Reduce Parts Failure Rate = Reduce Chance of Failure = Remove Failure Causes = Bigger Operating Profits Forevermore

The heading in the slide above tells us what to do if we want to improve reliability of plant and equipment. We must remove the chance of failure by proactively working to remove failure causes so there are no reasons to fail. If there is no failure cause there is no failure event.

Every time an equipment’s failure rate falls you will generate more operating profit. That is why reliability is so keenly pursued by CEOs, Executives, and Managers—raising reliability is a certain way to greatly increase operating profits.

In the list of the 15 ways a drinking glass can fail many of the failure causes can be removed with either design changes to the glass, procedure changes in how the glass is moved and handled, and with education and training that makes people more skillful in preventing the chances of failing a glass.

As we remove failure causes the rate of failure falls, because opportunities for something to go wrong are eliminated. The decrease in failure rate shows as improved reliability—fewer failures happen over a period, which implies a longer time between failures, and that is reliability improvement.

Remove failure causes and you get a lower failure rate. A reduced equipment failure rate saves money, because there are fewer breakdowns and operating problems needing to be fixed. The more you remove failure causes, the greater the operating and maintenance savings. Breakdowns and failures which no longer happen cut maintenance expenditure and operating costs.  reliability improvement is a very profitable strategy. And reliability is improved every time you intentionally remove failure causes.

Explanation Of Series System Reliability Property 1 For Plant And Equipment Reliability Improvement

You must lift the reliability of the worst performing items in a series system if you are to improve the system reliability.

Slide 32 – The Implications of Series System Reliability Property 1 When You Want Maximum Plant and Equipment  reliability improvement

Series System Reliability Property 1 is best explained with a simple example. The components shown in a series in the above slide have the reliability indicated in the boxes. The series system reliability formula is used to determine what the total system reliability will be. Its reliability is shown in the system box. You can see from the numbers in the boxes that the system reliability can never be higher than the least reliable component in the system.

The Business Effects of Series System Reliability Property 1

In the top two-item series system arrangement, the component with the lowest reliability is improved from 0.8 to 0.9. This is a 12% increase in reliability for the component. The consequential system reliability improvement is also 12%. When one of the components in the lower four-item series system arrangement is improved from 0.8 to 0.9 its reliability rises by 12.5%. The consequentially system reliability also improves 12.5%.

Series System Reliability Property 1 tells us that improving the least reliable component in a series improves the series reliability by the increased reliability of the component. The least reliable item in a series will limit the series reliability performance because system reliability can be no higher than the lowest reliable component.

When a “Bad Actor” item of plant has such low reliability it prevents the plant from achieving its best performance Series System Reliability Property 1 tells you to improve the reliability of the Bad Actor. Until its reliability is raised the operating plant’s reliability is always going to be lower than that of the Bad Actor equipment.

The Economics of Series System Reliability Improvement

The reliability of a series configuration can also be raised by other than fixing the Bad Actor item. You will surely lift system reliability by improving the 0.9 reliable item in the two-component system to 0.95 reliability. The system reliability will stay below 0.8, but it will rise from 0.72 to 0.76 (0.95 x 0.8 = 0.76). You don’t only need to focus on Bad Actor items to improve system performance.

We now arrive at an important economic issue when choosing which reliability improvements to make. When you spend money on improving equipment reliability the investment must have a strong business case justifying the expenditure versus its return-on-investment—the project’s ROI must have a great payback.

Say in the upper two-component system shown on the slide it costs $100,000 to take the Bad Actor equipment from reliability 0.8 up to 0.9 and lift system reliability to 0.81. If instead, you could invest $10,000 in the reliability improvement of the neighbouring equipment and lift its reliability of 0.9 to 0.95, what should you do? We can put some numbers into the system series reliability equation to determine the scale of the payback from each investment.

At present the system reliability is, 0.9 x 0.8 = 0.72. We know the $100,000 investment in the Bad Actor gets a system reliability up to 0.81. For the $10,000 investment in the 0.9 reliable item the new system reliability becomes 0.95 x 0.8 = 0.76, a 5.5% system reliability improvement. The $10,000 investment increases system reliability 5.5% while the $100,000 investment delivers 12.5% system reliability improvement. The lower cost investment delivers a better economic return.

Explanation Of Series System Reliability Property 2 For Plant And Equipment Reliability Improvement

Simplify, Simplify, Simplify your series systems to keep them simple and short.

Slide 33 – The Implications of Series System Reliability Property 2 When You Want Maximum Plant and Equipment  reliability improvement

An unfortunate aspect of Series System Reliability Property 2 is shown in the slide above—when you add an item into a series system the system reliability falls. In the slide, a third item of equal reliability is added into a series of two items. The numbers indicate what happens to the series reliability—it drops from 0.81 down to 0.73.

Having long series systems automatically leads to having more problems with equipment, and with the added work tasks that need to be performed because of the extra equipment. As a series system grows there are more components that can fail. The only way to keep system reliability the same when adding items to a series system is for each new item to be perfectly reliable, i.e. R = 1. Currently in the 21st Century, it is impossible for equipment to forever be perfect and reliable. Also, with added equipment in a longer series system operators and maintainers will work on them. When people do work on the extra items more opportunities are added where human error causes things to go wrong.

The Business Effects of Series System Reliability Property 2

The message from the discussion above about Series System Reliability Property 2 is clear: if you add more items to a series arrangement the series system reliability will drop.

To return the system reliability back to what it was before the addition of new items the reliability of other items in the series must also be improved.

There are options as to how to restore the three items series in the slide back to the original system reliability of 0.81. The reliability of each item, new and old, can all be raised to 0.932. Alternately, the reliability of selected items in the series can be raised so that in combination the effect is to deliver 0.81 system reliability.