Maintainability and Availability

Spares Management Guide & Case Study (Practical)

The management of spare parts and inventories is all about balance between the cost of stocking the parts and the costs and risks of not having them when they are required.

As a consultancy owner, one of the most overlooked issues I see in Industrial operations is the management of spare parts. I don’t have enough fingers, toes and limbs to count how many times I’ve heard the phrase ” The machine is down because we’re waiting on spare parts”.

I see this phrase normalised so often that people don’t bat an eye and have accepted it as the norm- a lot of maintenance professionals don’t focus on the effective management of this area . I think this is overlooked because it requires MATH to calculate- and just like poetry, most people hate math. [Read more…]

by Miguel Pengel Leave a Comment

Weibull Analysis Summary PDF and Case Study

A Weibull analysis is one of the most versatile tools in a Reliability Engineer’s toolbox. I have received many requests to start summarizing some of my articles and case studies into quick and easy PDF references for distribution.

[Read more…]

by Fred Schenkelberg Leave a Comment

The Basics of Planned and Deferred Maintenance

We can plan to do more than we are capable of accomplishing. The remaining items, if they warranty accomplishing become deferred. They roll over to the next’s day’s list of actions to take.

Of course, in practice, the process to plan, execute, and defer maintenance activities is a bit more complex than described above. The ability to maintain equipment in working order along with minimizing downtime and costs is in large part the balance between resources available to conduct maintenance and the increased risk of system failure due to deferred maintenance. [Read more…]

by Fred Schenkelberg Leave a Comment

Implementing the Right Preventative Action

There are two instances when you should implement preventative action. First, once a failure occurs and you would like to avoid similar future failures. Second, before a failure occurs, yet an undesired failure mechanism is likely to occur.

Like corrective action there is a wide range of possible preventative actions. The selection of the right actions requires considering customer expectations, business and legal factors, along with the technical and economic feasibility. [Read more…]

by Fred Schenkelberg 4 Comments

Preventive Maintenance Goals and Activities

Preventive Maintenance or PM is a set of inspections and tasks that help prevent equipment from failing. Keeping equipment operating improves plant capacity and throughput. Avoiding unwanted downtime helps the plant avoid unnecessary expenses and lost productivity.

Checking the oil level in your car’s engine and adding more as needed, along with regular oil changes are examples of PMs. [Read more…]

by Fred Schenkelberg Leave a Comment

Optimizing Maintenance

One of the considerations when planning maintenance is the timing of the replacement of parts of the system. In some cases it makes sense to wait for the item to fail, sometimes, it makes sense to place it on an interval or set an amount of operating time, and yet in others, we can measure indicators that a replacement is necessary.

In order to make these decisions, we need data.

According to O’Connor and Kleyner (Practical Reliability Engineering, 5th Ed.), we need specific information for each part. The following list outlines the recommended information. [Read more…]

by Fred Schenkelberg 2 Comments

4 Electronics Nondestructive Evaluations

It is possible to use the circuit design or the circuit itself to evaluate electronics. This ranges from checking if the system is wired correctly (the right parts are present and attached properly) to a complex evaluation including the proper functioning of firmware and attached software.

Beyond visual inspection, we need a way to evaluate the microscopic structures with today’s electronic components.

The ability to provide inputs and measure outputs provides one view and in most cases is nondestructive. [Read more…]

by Fred Schenkelberg 3 Comments

8 Nondestructive Evaluation Techniques

There are times when we need to evaluate a product to determine is it assembled correctly or when looking for clues concerning a failure mechanism. Simple visual inspection may be sufficient and there are times when we need more information or detail.

A great first step is the use of an appropriate nondestructive evaluation (NDE) method.

Done correctly, we keep the item unchanged and available for shipment or further inspection.

[Read more…]

by Fred Schenkelberg 5 Comments

8 Factors of Design for Maintainability

The first time I changed the oil filter of my car (first car in high school) I smashed my knuckles against a grimy block of metal. More than once. It may have been my lack of experience or improper tools. Or, it may have been a rather poor design.

Watching the Indy 500, especially the pit stops, I quickly realized there has to be something different about those cars that lets them change tires, add oil & fuel, and clean the windshield in less time than it took me to get under the hood and find the oil filter. The cars were designed differently and that is what permitted the difference in service time.

In order to increase availability and minimize the cost of maintenance, we have to deliberately design the system to accommodate the needs of maintenance. [Read more…]

by Fred Schenkelberg 2 Comments

Corrective Action Question

When this posts I should be near 17k ft altitude without electricity or internet – hoping for the best. So, this post and the next couple are homework for you. Take a look, work the problem, solve it, then show your work. Comment with why you choose your response and why you didn’t select one of the others.

Here is question 18 from the ASQ CRE 2009 sample exam. [Read more…]

by Fred Schenkelberg Leave a Comment

Fault Isolation

I’m about to leave for Nepal for a month and much of it without internet. So, this post and the next couple are homework for you. Take a look, work the problem, solve it, then show your work. Comment with why you chose your response and why you didn’t select one of the others.

This is question 17 from the ASQ CRE 2009 sample exam. [Read more…]

by Fred Schenkelberg 1 Comment

Reliability Centered Maintenance

The document by Nowlan and Heap

Part of keeping equipment operational is affecting repairs appropriately. Sometimes it makes sense to replace an element of some equipment before it fails, i.e. automobile tires as the tread wears. Sometimes is doesn’t make sense to repair a functioning unit as the result would be a system that is less reliable then before. [Read more…]

by Fred Schenkelberg 5 Comments