Quality Lifecycle Management: Striking a Balance between Product Reliability and Over-Design

Quality Lifecycle Management

When it comes to product design, companies must balance four competing goals: cost, time to market, feature set, and reliability. The key is to get the right mix and create the greatest customer satisfaction with the product.

Too often, however, companies downplay the importance of reliability when weighed against the other three goals. They prioritize cost, time to market, or feature set over reliability. As a result, they aren’t aware of poor reliability until the product has been released and they ultimately incur higher lifecycle costs and lower customer satisfaction due to product failures, excessive warranty claims, and, in the most unfortunate cases, liability claims from safety incidents.

Even when companies do focus on reliability, they often fail to take a comprehensive approach throughout the product lifecycle. Instead, they try to fix reliability issues with ad-hoc analyses only when serious issues emerge. This “band-aid” approach fails to address reliability in a holistic manner and misses the chance to reap the benefits of a more integrated program.

To avoid this outcome, companies should include reliability in up-front design decisions, and develop formal processes for analyzing and improving the reliability of the product throughout its lifecycle. Quality Lifecycle Management (QLM) provides the processes and tools to do just that.

QLM is a systematic way to build the right amount of reliability into a product. It works by making it possible to plan, predict, and simulate a product and operating conditions to ensure product designs will meet specified reliability and lifecycle cost targets once in the field. QLM standardizes and connects quality processes throughout each stage in the product lifecycle, calling upon enterprise tools to gather and share knowledge. It consists of setting realistic goals for reliability and availability, measuring those goals through design and prototype testing, and tracking field failures to determine how well those goals are being met post-production.

Finding the Sweet Spot

All that said, to minimize the lifecycle cost of a product, it is important to consciously decide how much reliability to build into the product while still addressing key criteria for cost, time, and features. The key is finding the sweet spot between too little and too much reliability. The more reliability is built in during the design phase, the higher the design and manufacturing costs due to the price for higher quality parts, redundancy, higher R&D personnel counts, or more complex manufacturing processes. The goal is to strike a balance so that a product is reliable enough to avoid costly post-production claims without over-designing.

For example, because consumers generally upgrade their cell phones every few years, manufacturers do not bother building ultra-robust phones (which would eat into profit margins). Instead they need to build in enough reliability to avoid major issues for a two- or three-year window.

On the other hand, an automobile manufacturer cannot risk low reliability in its braking system as this could lead to injuries or even deaths that irreparably hurt the company’s reputation and lead to exorbitant costs in court.

Although their situations are different, both the cell phone company and the automobile company can minimize their costs by planning and tracking the quality of each product through its product lifecycle.

No matter how much reliability a manufacturer decides to build into its product, QLM is a proven way to ensure the company achieves its goal.

Quality Lifecycle Management is the Foundation of a Systemic Approach

Success with QLM depends on following a standardized quality management process, which addresses the following:

  1. Plan for reliability: Allocate reliability requirements to subsystems and conduct initial risk analysis using a fault tree and Failure Modes & Effect Analysis (FMEA) to systematically identify all of the potential failures throughout a system and develop controls to minimize or prevent their occurrence or effects.
  2. Design for reliability: Predict reliability based on the product structure, conduct maintenance task analysis, design a reliability block diagram, perform a component FMEA, create a fault tree, and estimate the product lifecycle cost.
  3. Analyze manufacturing process: Perform a process FMEA to determine the ways in which gaps or failures in the manufacturing processes can affect product quality. Also design control plans to identify and minimize variations in the manufacturing process.
  4. Test reliability of prototype: Create design verification plans, conduct accelerated life testing, and analyze test failure data using a Weibull analysis.
  5. Analyze and improve post-production quality: Implement a Failure Reporting and Corrective Action System (FRACAS) to continually improve product quality. Analyze failed units for root causes and put into place corrective actions. If it’s possible to capture or estimate the product’s operating time, it’s possible to compare field reliability to the design reliability goal. Going forward, field quality can be improved using CAPA, Nonconformance Management, and Complaints & Customer Feedback tools.

By following this well-defined process, companies can realize significant value from PLM. Managing quality in an integrated way throughout the product lifecycle helps manufacturers achieve the right balance across the key criteria of reliability, cost, time, and features.

While a QLM process delivers tremendous value, it can be challenging to successfully implement this process. We’ll tackle those issues in a future post.

About Karen Bowman

Karen Bowman is a Senior Reliability Consulting Engineer at PTC. As an ASQ-Certified Reliability Engineer (CRE), Karen has performed FMEAs, Fault Trees, Weibull analyses, MTBF Predictions, RBDs, and various other reliability and quality consulting projects for hundreds of customers. Karen has also deployed large-scale FMEA systems and trained employees on their customized FMEA process. She received her BS in Electrical Engineering at Lawrence Technological University and her MS in Electrical Engineering at The Pennsylvania State University.
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One Response to Quality Lifecycle Management: Striking a Balance between Product Reliability and Over-Design

  1. Pingback: Quality Lifecycle Management: 4 Steps to Success | PTC

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