To remain competitive and avoid unplanned downtime, your organization needs to optimize maintenance costs for the industrial equipment you rely on for daily operations. It’s best to adopt a systematic approach involving fault tree analysis. FTA can help you increase the mean time between failures in your facility.
This article explains why industrial organizations conduct fault tree analysis. It provides a fault tree analysis example to help illustrate the benefits of FTA.
What is fault tree analysis (FTA)?
Fault tree analysis is a top-down, deductive failure analysis used to identify the root causes of system or equipment failures. The goal of FTA is to break down potential failure points and understand how these issues may contribute to larger system breakdowns.
How fault tree analysis works
Here’s an overview of how companies use FTA in real-world situations.
- Logical diagram: FTA uses a tree diagram, starting from the top event (failure) that is causing concern in your facility. Then, you fill in details in the failure analysis tree to break down possible causes for failure and break down these causes into intermediate events and basic events. An intermediate event has an input and output in the diagram. Basic events refer to the main cause of the top event, and you place them at the bottom of your fault tree.
- Logic gates: You identify logic gates (using Boolean logic). An OR gate indicates that the top event will happen if any input event occurs, while an AND gate requires that each input event must take place to cause the failure (top event or primary issue) to occur.
Key steps in conducting a fault tree analysis
There are four main steps when carrying out a fault tree analysis.
Step 1: Define the failure: Your initial task is to clearly identify the main failure event or problem that needs to be analyzed.
Step 2: Identify possible causes: Break down possible causes using logical gates, focusing on intermediate and basic events.
Step 3: Construct the tree diagram: A tree diagram gives you a visual representation of the failure pathways for a comprehensive look at what’s ailing your system. Use different symbols in your fault analysis tree.
For example, the “top event” symbol is a rectangle with one line pointing out of the bottom to indicate a single input without relative outputs. In comparison, the symbol for an intermediate event has one line at the top and one line at the bottom of the rectangle denoting the input and output.
Step 4: Analyze the tree: Next, it’s time to evaluate the causes, determine the most likely failure paths and prioritize preventive actions.
Practical example of a fault tree analysis for maintenance
Here’s a common scenario to illustrate using FTA for maintenance. A manufacturing facility experiences frequent conveyor belt failures, resulting in costly downtime. Using fault tree analysis, you would follow these steps to conduct a root cause failure analysis.
Step 1: Define the top event: Conveyor belt failure
Step 2: Identify potential causes: Your technicians need to examine the conveyor belt to check for the source of the problem, which could be:
- Motor failure
- Belt misalignment
- Overload on the conveyor system
Step 3: Break down the causes using logical gates:
Motor failure: Failure of a conveyor belt system’s motor may be caused by insufficient lubrication or electrical issues. To keep your conveyor belt running properly, it’s essential to schedule regular mechanical lubrication and perform ongoing checks of the electrical system to catch problems while they’re still relatively small and easier to address.
Belt misalignment: You may determine that the belt fell out of alignment due to worn rollers or faulty condition monitoring sensors. Replacing old rollers and upgrading the sensors can help you keep this problem from occurring again.
Overload: With overloads typically resulting from improper load management or mechanical defects, the FTA will guide you about running the conveyor system within the manufacturer’s guidelines or identify what steps to take to repair or replace defective parts. For example, you might have inadvertently exceeded the system’s maximum load capacity or put too much stress on the conveyor belt because you’ve increased production volume.
Step 4: Analyze and implement preventive measures: In FTA, once you’ve identified the cause or causes of malfunctioning equipment, such as a conveyer system, it’s time to set up a schedule to monitor it and prevent problems from reoccurring.
For example, you’ll arrange for your team to conduct regular motor inspections and periodically calibrate the system.
Because a properly functioning conveyor belt is crucial to an optimized logistics chain inside your facility, you will also want to check your load management systems or deploy an upgraded system. Doing so helps you determine the maximum load capacity while operating the conveyor system safely.
Benefits of fault tree analysis in industrial maintenance
You and your colleagues will want to remember the main benefits of FTA as you work to improve your industrial maintenance protocols, boost worker safety and curb costs.
- Preventive maintenance: FTA identifies weak points in equipment and systems, allowing your team to take preventive action before major failures occur. Naturally, it takes less time, money and other resources to fix problems when they’re still relatively small.
- Improved safety: By identifying potential hazards and failure modes, FTA enhances safety protocols and reduces the risk of accidents. Your company’s safety officer should carefully consider FTA’s role in ameliorating hazardous conditions. When conducting a fault tree analysis, you will want to hear from diverse viewpoints among your team for better insight into the root of the problem.
- Cost reduction: Reducing the likelihood of equipment failure minimizes downtime and costly repairs. Instead of failing to meet production milestones, you can maintain efficient operations thanks to maintenance tasks prompted by FTA.
The importance of FTA in preventing breakdowns and improving safety
Working through the FTA is vital for improving worker safety and avoiding costly breakdowns. The diagram you construct during FTA helps you define the failure, identify the most likely causes and prepare for repairs and maintenance to minimize downtime.
Conducting an FTA gives you a treasure trove of information about what went wrong with an industrial system, which you then analyze to devise a plan for repairs and preventative maintenance.
The professionals at Advanced Technology Services can assist you with predictive maintenance analytics, short and long-term maintenance and so much more. Contact us today for expert assistance with your maintenance strategy.
