At Pure Prime Solutions (PPS), we develop client-specific equipment and testing processes. Typically, performance and reliability testing is performed in-house and occasionally outsourced to an independent consultant. Conventional wisdom leads most to believe that you want to conduct product testing in-house. Yet, that is not always the case — most importantly, because of the cost.
Maintaining testing equipment is expensive. It requires dedicated space, equipment, upgrades, labor, and, most importantly, training. Typically, during product development, testing is performed to validate that the design meets performance, durability, and reliability requirements.
Above all, the best reason for outsourcing product testing is adding added engineering experience when you need it the most. Product testing is a manufacturer’s last opportunity to find and resolve weaknesses in the product design. PPS doesn’t typically just run your Test and provide you some data to figure it out on your own. PPS partners with our clients to ensure that it adds value to the product before we perform any testing. Delivering this value requires a deep understanding of the true objective of the Test to determine what is the lifetime performance, durability, and reliability of the product.
Performance is usually the easiest to understand and test. Why? All products are intended to perform a task or function that adds value to its consumers. Added value is gained from increasing productivity that decreases production cost-per-unit. The amount of value added is determined compared to the current or required cost of that task. However, a product’s performance doesn’t reside in a vacuum. The dependability and reliability of the product must meet its expected operational life. In short, cost-effective product design requires balancing performance with durability, reliability, and product lifetime total cost. Cost-effective designs require performance, durability, and reliability testing.
Durability and Reliability Testing
Durability and Reliability Testing measures a product’s performance and endurance over long periods of time, operating in its intended environment. To understand the reliability of a product during its lifetime, we need to graph the failure rate over time, creating the bathtub curve. The bathtub curve gets its name from the shape of the graph. The beginning and the end of a product’s lifetime are where the highest rate of failure occurs.
The bathtub curve shows that the failure rate during the early “infant mortality” of a product decreases with time. Infant mortality is typically the first concern of any manufacturer, and this often leads to over-designing the product and pushing the product cost higher. Fortunately, these types of failures occur early in the testing process. Infant mortality provides the opportunity to resolve the issue and remove the failure mode quickly. Infant mortality results in the development model failing fast and often.
After the infant mortality phase of a product’s life, product failures occur randomly. In our experience, these random failers arise because of the manufacturing process and environmental variation or abuse. Finally, due to wear-out, product failures begin at the end of life. Additionally, there is a need to perform durability and reliability testing for a few reasons:
- To examine a product’s endurance. (e., How long will it last?)
- To determine the failure rates of the product. (MTBF)
- To determine preventative measures that can increase the product’s reliability and lifespan. (What broke when and how do I fix it?)
- Validate a product design for service. (The design meets the client’s expectations)
For any product to have value, the mean time between failures (MTBF) needs to match the product’s expected total cost. For example, PPS designs its products to last twenty (20) years without significant repair. That translates into the MTBF be forty (40) years. Why? Because MTBF means that at the twenty (20) year mark, fifty percent (50%) of your produced products have failed beyond repair due to wear-out.
How can we test to failure without waiting for the life of the product?
PPS performs Highly Accelerated Life Testing (HALT) and Highly Accelerated Stress Test (HAST). These tests are designed for the environment and expected use of the product during its lifecycle. HALT and HAST are completed in months, without waiting for the life of the product. The Reliability test examines five primary areas:
- Vibration and Noise
- Temperature and Humidity
- Time Duration
- Number of Test Cycles
- Test Duration
Well-designed and manufactured products minimize unforeseen disruptions in performance throughout the duration of their life. Thorough testing exposes these unexpected disruptions and the root cause condition in which they occur.
When you need Performance, Durability, Reliability Testing, or some combination thereof, PPS will simulate the environmental factors to determine your products’ operating limits.