If your company makes planes, trains, automobiles, medical devices, computers, and communication systems, or you are a large electronic device supplier, the reliability of your products in the field is crucial to your business success. The growing market for electric and hybrid vehicles is increasing the pressure on life-time performance of the devices that power them.
The energy demands of both consumer and industrial electronic systems are increasing, and electronics power component suppliers as well as OEMs are faced with the challenge of providing the highly reliable systems needed for aviation, electric vehicles, trains, power generation, and reusable energy production.
What is Reliability?
Reliability is the ability of a product to properly function:
within specified performance limits
meaning that the product must function within certain tolerances in order to be reliable.
for a specified period of time
meaning that the product has a useful life during which it is expected to function within specifications.
under the life cycle application conditions
meaning that reliability is dependent on the product’s life cycle operational and environmental conditions.
What Causes Products to Fail?
Generally, failures do not “just happen.” Failures may arise during any of the following stages of a product’s life cycle:
Product design
Manufacturing
Assembly
Screening
Testing
Storage
Packaging
Transportation
Installation
Operation
Maintenance
When a Product Fails, There Are Costs:
To the Manufacturer:
Time-to-market can increase
Warranty costs can increase
Market share can decrease. Failures can stain the reputation of a company and deter new customers.
Claims for damages caused by product failure can increase
To the Customer:
Personal injury
Loss of mission, service or capacity
Cost of repair or replacement
Indirect costs, such as increase in insurance, damage to reputation, loss of market share
What is a Root Cause?
The root cause is the most basic causal factor or factors that, if corrected or removed, will prevent the recurrence of the situation.
The purpose of determining the root cause(s) is to fix the problem at its most basic source so it doesn’t occur again, even in other products, as opposed to merely fixing a failure symptom.
Identifying root causes is the key to preventing similar occurrences in the future.
What is Root Cause Analysis?
In order to avoid the above, when a product or device fails, you need to understand why.
Root cause failure analysis helps a company get to the source of a product failure. More importantly, it provides the manufacturer with the information needed to address and correct the issue causing the failure.
Root Cause analysis has four major objectives:
Verify that a failure occurred;
Determine the symptom or the apparent way a part has failed (the mode);
Determine the mechanism and root cause of the failure;
Recommend corrective and preventative action.
To note that Root Cause Analysis is different from troubleshooting. While troubleshooting is generally employed to eliminate a symptom in a given product, or to identify a failed component in order to do a repair, the root cause analysis is dedicated to finding the fundamental reason why the problem occurred in the first place, to prevent future failures.
Achieving Improved Reliability with failure Analysis
Determining the root cause of a failure is a three-part process.
1. Data Collection
The objective of data collection is to understand the events and the major causal factors associated with the incident that led to the failure.
The evidence gathered will be used to identify the critical aspects of failure, including the failure mode, site, and mechanism, time in the life-cycle where failure occurred, length of time required for the failure to initiate, and periodicity of the failure.
The 5-Ps of data collection:
People
Physical evidence
Position (physical, time-event sequences, functional relationships)
Paper (procedures, manuals, logs, e-mails, memos)
Paradigms (view of situations and our response to them)
Data gathering must be performed as soon as possible after the event occurs in order to prevent loss or alteration of data that could lead to root cause.
A huge amount of information is not the goal of data collection. Unrelated data often cause confusion.
Hypothesizing Causes
Hypothesizing causes is the process of applying knowledge of risks associated with a product’s design and life cycle to the data gathered about the failure event, in order to postulate a root cause.
Tools for hypothesizing causes:
Failure modes, and effects analysis (FMEA) and Failure Modes and Criticality Analysis (FMECA)
Fault tree analysis (FTA)
Cause and effect diagram – Ishikawa diagram (fishbone analysis)
Pareto analysis
Failure Modes and Effects Analysis (FMEA) is used to identify the ways in which components, systems or processes can fail to fulfil their design intent and identifies:
All potential failure modes of the various parts of a system,
The effects these failures may have on the system,
The mechanisms of failure, and
How to avoid the failures, and/or mitigate the effects of the failures on the system.
Failure Modes, Effects and Criticality Analysis (FMECA) extends an FMEA so that each fault mode identified is ranked according to its importance or criticality.
In contrast with the “bottom up” assessment of FMEA, fault-tree is a “top down” analysis that starts qualitatively to determine what failure modes can contribute to an undesirable top level event.
It aims at developing the structure from which simple logical relationships can be used to express the probabilistic relationships among the various events that lead to the failure of the system.
2. Analyze Data Collected to Determine Root Cause Failure and Corrective Actions
Reviewing in-house procedures, e.g., design, manufacturing process, procurement, storage, handling, quality control, maintenance, environmental policy, safety, communication or training procedures, against corresponding standards, regulations, or part- and equipment vendor documentation, e.g., part data sheet and application notes, equipment operating and maintenance manuals, can help identify causes such as misapplication of equipment, and weakness in a design, process or procedure.
Example 1: misapplication of a component could arise from its use outside the vendor specified operating conditions (e.g., current, voltage, or temperature).
Example 2: equipment (e.g., assembly, rework or inspection equipment) misapplication can result from uncontrolled modifications or changes in the operating requirements of the machine.
Example 3: a defect may have been introduced due to misinterpretation of poorly written assembly instructions.
3. Failure Analysis Tests
Root cause failure analysis uses a variety of tests to determine the true source of a product failure. These tests are divided into two categories: non-destructive tests, which keep a product intact; and destructive tests, which require the product to be altered in order to examine cross-sections or thermal behavior.
Non-Destructive Testing (NDT):
Visual Inspection
Optical Microscopy
X-ray imaging
X-ray Fluorescence Spectroscopy
Acoustic microscopy
Residual gas analysis
Hermeticity Testing
Destructive Testing:
Thermal Analysis
Destructive Physical Analysis (DPA)
Cross-section Analysis
Consistently bringing high-quality and reliable products to market requires an optimized engineering workflow in product design – one that allows the developer to quickly run through tens of hundreds of different design alternatives without hindering an on-time delivery. How do companies achieve this? They use an automated simulation solution.
Leading companies have turned to simulation solutions that enable companies to move nimbly through their product design process without overspending on overhead. The benefits of simulation far outweigh the start-up cost and setup in the long run, since it provides a risk-free, low-cost environment that allows designers to consider hundreds, if not thousands, of iterations of the same design.
Simulation as a part of product development is widespread. The use of simulation as a means of addressing the challenges of increased product complexity and improving reliability is the overriding theme.
Under the constant pressure to launch truly innovative products in a rapid and reliable fashion, companies need the ability to meet consumer needs while maintaining profitability. For top companies, this means using a simulation package solution. In order to properly take advantage of the benefits of simulation, companies should look for solutions that enable the exploration of different design alternatives across varying environments. For proper implementation of simulation into product development, follow these steps:
Front-load the product development process.
Make your most rigorous analysis and proofing during the first few stages. Early-stage changes are easily adapted and less costly than changes during production. The sooner design iterations are explored, the more flexibility for change is possible and the less room for error downstream. The easiest way to implement this exploration is using simulation and virtual prototyping.
Adapt technology to fit your people and processes.
Add solutions that are easy to use and will integrate into your process easily. Keep in mind that any new solution will require training, which should be considered a critical part of integration. Use simulation solutions that will aid in reducing errors during design and functionality and fit with the existing process.
Use solutions that help with design standardization and organizational record-keeping for “lessons learned” and downstream debugging.
Best-in-Class companies are 33% more likely to use simulation in post-manufacturing failure analysis.
Keep tight collaboration between testing and design teams.
Solutions that improve product performance can only be used effectively if that information is passed on to the designers.
Companies can significantly reduce their production costs, decrease delays to market, and improve their product reliability by taking the right steps to effective implementation of testing and simulation in their product development. This requires a systematic approach across the entire enterprise, by deploying testing and simulation solution capabilities to equip users to work efficiently and productively.
Interested in more insights and best practices like this? Sign up to get the best industry insights, tips, and trends from ETS Solutions Asia in your inbox each week!
