Design Phase

Reliability Predictions (MTBF)

Customers and markets are requiring product development teams to predict the product reliability in terms of MTBF. The resulting MTBF has various applications such and comparing design strategies, trade-off analysis, system availability, spares analysis, purchasing decision, cost of ownership, There are a number of standards that are used based on different customer & market requirements. The MTBF numbers are key drivers in calculating system / product availability.

There different levels of reliability predictions based on customer requirements:
  •  Parts Count Method (Assembly or System Level) – it estimates the reliability of the product utilizing any industry standards such as Telcordia SR-332 for commercial products and MIL-HDBK-217F generally applied to defense products.
  • Part Stress Method (Assembly or System Level) – this method provides more accurate results since it uses the operating stress such as electrical, temperature or quality factor of components vs. parts count that uses default electrical stress levels.
Product Aging (End-of-Life) Predictions

Once the part stress product reliability prediction is performed, end of life prediction is performed. We have two levels of end of life predictions basic and advanced.

  • Basic Level - this analysis calculates the product end of life by focusing on elements such as FANs, SSD, HDD, and electrolytic capacitors.
  • Advanced Level – at this level we perform detailed analysis of your silicon technology based the latest advancement in the industry.

Both of these activities help companies to determine the cost of their service level agreements (SLA), warranty, re-call reserves, cost of ownership and overall contract negotiations.

System Availability (Markov) Analysis

Depending on product types and market requirements, there are various levels of availability that each must product must achieve. The product availability can be expressed in terms of % availability, downtime or DPM. There are a number of inputs that goes into this calculation such as MTBF that is calculated through reliability prediction and mean time to repair (MTTR) that is calculated through the system fault management evaluation and maintainability analysis. Availability analysis is performed at different stages of product development. It is used in the early concept / design phase to provide the recommendations on product architecture such as redundancy, switchover strategies that can have different level of impact on the product design and schedule. In the later phases it is performed to ensure the overall system design meets the intended customer requirements. Spares depot infrastructure plays a role in this calculation as well.

Reliability Block Diagramming (RBD)

This is an easy and straightforward method to communicate reliability shortcomings to the design team. It uses blocks to model various elements of the system and can be used for analysis such as reliability allocation and architectural enhancements. For the detection time & probability Markov analysis is used, but to determine the required redundancy block diagramming is sufficient. It shows the relationship between blocks from ingress to the egress of the system. The key inputs are the system Bill of Material (BOM) or system functional block diagram. The block MTBF can come from BOM of each block, vendors, pervious generations, competitive analysis or past field data.

Failure Modes Effects Analysis (FMEA) & Criticality Analysis (FMECA)


The goal is to highlight potential issues in the design or processes and identify a mitigation strategy to lower its risk of occurring and its impact on the system. It is a risk management tool that can be used in the early hardware or software design phases or for the manufacturing processes. The FMEA/FMECA can be tailored for various applications. It is a method to identify, evaluate and controlling the risk before impact the customers. It is recommended to perform FMEA/FMECA before tests such as HALT, Fault Insertion Test or RDT to the level of stress that will be applied to the product, its detectability and potential long-term reliability issues. It can be performed at system, subsystem or component levels. We design tailored FMEA template for each product based on its requirements and applications.

Customers have two options for the FMEA/FMECA. We can either provide facilitations or perform the actual FMEA/FMECA. The risk level and scoring mechanism will be developed in collaboration with the customers in order to ensure customer views and challenges are expressed in the parameters used in the FMEA/FMECA. Using different tools or just Excel spreadsheets can perform this analysis.

De-rating Analysis & De-rating Guidelines

We work with our customer to develop a de-rating guideline to be used for the stress de-rating analysis or we apply customer current re-rating guidelines to perform this activity. The goal is to identify the components are overstressed and are at or above the de-rating levels. This technique allows the designers to build in reliability in their design through margin management. This is the single most effective way to improve short or long-term reliability of the product based on its market and customer requirements. One method that can be used for a quick testing of the design margins is HALT, which is designed to identify issues with design margins.

Warranty Predictions

The goal of this analysis is to help the organization to determine the most impacting event in the warranty and how to mitigate the situations which at the same time improves manufacturing and warranty cost. It includes options based on development method, manufacturing and cost of warranty. We will provide recommendations on how to reduce warranty cost from early product design phase.

Maintainability Analysis
All products have a probability to fail. Maintainability analysis focuses on how to determine the amount of time required to repair a system once it fails. It measures the process and speed of restoring the system after a failure has occurred. Some quantifiable measures are mean time to repair (MTTR), Mean Time to Restore, Mean System Downtime. It helps with the number of repair stations, spare parts and preventive maintenance schedule & associated tasks. Some of the inputs to this analysis are failure detection & isolation time for the specific assembly/system element, replacement time and finally the time to ensure everything is working.