The Purpose of Reliability Engineering Work
An immediate purpose is to earn a living. You also may suggest the work is to improve the reliability of the product or system. Reduce downtime, reduce warranty, increase profit, etc.
That is fine for the overall purpose of reliability engineering work, yet in the day to day work, the specific task level, what is the purpose behind what we do?
What do Reliability Tasks Provide?
In the day to day work of a reliability engineer, they receive requests, create plans, conduct experiments, analyze data, etc. These seem a few steps away from directly reducing warranty or downtime. Keep in mind that reliability engineers rarely directly change an item’s design, supply chain, warranty policy, or pretty much anything. So what is it we do that results in someone keeping us on the payroll?
Let consider the analysis of the reported failures from the past month. This may be a routine task to gather and report monthly field failures. One way to analyze the data is to create a Pareto Chart. Ok, so we have a graphical listing of the failures from most frequent or costly to least.
So what? What does this chart provide those that review (study?) the chart? If coupled with the idea that resolving the most common failures leads to the most significant reduction in field failures, then the Pareto analysis provides the conversion of a pile of data (listing of the month’s field failure reports) into information (identification of most common field failures).
The chart does not fix the problem. It informs decision-makers to direct resources in a particular direction. Instead of resolving the root cause of the first (or most recent or most interesting), the Pareto chart provides a means to identify the best field failure to resolve.
An accelerated life test results in the expected time to failure estimate for an item. Information.
A highly accelerated life test results in the identification of likely failure modes or mechanisms for an item. Information.
A failure modes and effects analysis study provides a listing of the most serious consequence and/or frequent occurrence of potential failures for an item. Information.
A reliability block diagram provides a framework to allocate reliability goals to subsystems and enable estimating system reliability given subsystem reliability estimates. Information.
Information Leads to Better Decisions
Better such as working on solving the most important past or potential field failures. It is better to select a component technology that expects to survive without failure over the product’s expected lifetime.
Let’s say you have two potential vendors able to provide a critical part for your system. Each vendor’s solution is slightly different, thus not interchangeable, allowing you to source the part from either vendor. You need to pick one solution, one vendor, to incorporate into your system.
At this point, you have essentially two black boxes. Two claims of viable solutions for the immediate problem. Which do you select? The vendor that provides a better presentation and an excellent lunch? The vendor that demonstrates the most features or lowest price?
How about which solution will work in your system’s expected operating environment over some timeframe? How will the environmental stresses affect the vendor’s solution when customer’s use the system? While these factors may not always be part of a vendor selection decision, if they are, that is something a reliability engineer can sort out.
There are many ways to analyze and/or experiment to create the necessary information to address environmental stresses and time to failure. Let’s say we are concerned about the amount of vibration the system experiences in use. So, we run a simple experiment applying a vibration profile similar to that expected when in use.
If both solutions survive equally well, then either solution will work relative to the experimental results.
If one solution works while the other does not, that suggests a reliability-related preference for one vendor over the other.
If neither solution works, it may be time to find another potential solution or alter the design to minimize the vibration experienced by the vendor’s component.
In this simple example, the environmental stress test creates some information concerning the potential solutions’ ability to operate without failure, given the applied stress. The results inform the decision-maker, who then, along with all the other factors involved, can make an informed, thus better decision.
Reliability Engineering Work Provides Information
Consider every task. If you examine the results of the task, it is just information. Information that others use to make decisions concerning concept, design, marketing, supply chain, manufacturing, maintenance, and customer purchase decision.
The key here is to understand the decision that is being informed by a specific task. Will the results of the task create the appropriate or sufficient information for the pending decision? If not, time to find a better way to create the necessary information.
Well informed decisions reduce warranty or downtime, increase reliability performance and profit, etc. Being the one providing this valuable information is a great way to earn your living, too.
What decisions are you supporting today?
Also published on Medium.