Design Risk Analysis

[Vishwadeep Khatri]

Q. 134  What are the common tools for Design Risk Analysis? Explain their usage briefly.

 

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[Rupinder N]

The various Design Risk Analysis tools that can be used, and may eventually feed into a System, Sub System or Component level DFMEA are listed below:

QFD - It provides a logical and structured method of translating the customer expectations (VOC ) into design requirements. A QFD cascade model can be used to eventually get to production and quality control inputs as well. This is a great tool to highlight apparent inconsistencies between the customer asks, risks and design requirements.

Parameter (P) Diagram - It provides a visual representation of the inputs, parameters and the control factors in a product designed for a certain output. The design of the product should be such that it gives a desirable output, notwithstanding the noise factors. Though, time intensive, this can serve as a great input to DFMEA at System and Sub System Level, and sparingly used at a component level. 

Function Tree - It shows a preliminary listing of functions and their hierarchy or relation to each other. It helps visually showcase the dependencies amongst the various functions of the systems and can very clearly outline the risks, too.

Boundary (Block) Diagram- It is a visual tool that showcases the entire design or system or subsystem complete with the interfaces between various parts. The block diagram can also help identify the boundaries of risk analysis - in scope and out of scope.

Failure Mode Avoidance - This structured approach is used in early design phases to identify and detect all failure modes and hence select a design that fails the least (or has the least associated risks)

Fault Tree Analysis - It is a deductive failure analysis tool used to predict risks, or potential failures using a hierarchical approach and failure logic - hence it is a combination of probabilities and logic. It is used to uncover root causes for a potential failure by forming a qualitative model.

Design Failure Mode and Effect Analysis - All of the above tools can feed into DFMEA at different levels to complete a robust risk analysis.

 

 

[Prashanth Datta]

Before delving into the tools used for Design Risk Analysis, let us try and break down this question further to understand,

• What “Design Risk Analysis” means,
• Understanding what “Risk” is, and
• Common tools used for Design Risk Analysis.

What is “Design Risk Analysis”?

As we are aware, we have two methodologies in Six Sigma

1.     DMAIC – Define, Measure, Analyze, Improve  and Control --- Typically used for improving existing processes or products

2.     DMADV – Define, Measure, Analyze, Design and Validate/Verify – Typically used for developing or redesigning new products or processes

 

While performing a DMAIC methodology on an existing product or service, post Analyze phase, it is quite possible that the potential solution could call for a redesign of existing product or process in order to meet the Voice of Customer or Voice of Business. In such a scenario, it is extremely important for the project team to meticulously work on the design process, as it is the expected solution and hence it needs to be made full-proof.

 

One of the key focus areas in making the design full-proof is to anticipate the possible failures, threats or flaws of the proposed new design. 

 

In summary, we need to determine the potential risks associated with the revised design and build mitigation plans in advance, so as the product or process under the new design fulfills the VoC or VoB. Design Risk Analysis helps achieve this objective.

 

What is Risk?  

Any variable that has the potential to negatively impact your (re)design of a product or service which in turn can affect your project deliverables or output. Further, these risks, if unmitigated can have subsequent impact on various parameters like company brand, revenue, legal or statutory compliance etc., depending on the final deliverable or desired response / output (Y) of the project.

 

Common Tools used to identify Design Risks.

We can categorize these tools under two buckets

a.     Qualitative

b.     Quantitative

 

Qualitative tools for Design Risk Analysis

Documentation Review – In this approach, we try to identity risk by reviewing project related documents such as risk lessons learnt from similar projects, whitepapers or articles pertaining to the scope of project etc.,

Information Gathering Techniques - In this approach, we use tools like Brainstorming, Delphi technique, Interviewing etc., Essentially, with the planned (re)design scope, we gather inputs on potential risks from individuals, project team, stakeholders, subject matter experts either through 1x1 discussions, group discussions or anonymous feedbacks.  

Simple root cause Analysis technique like “5 Whys” can also help identify risks as we try to narrow down the root causes leading to new design.

Diagramming Techniques – Using tools like Cause and Effect diagram or Process flow charts help us break down the process in detail to identify potential risks.

SWOT Analysis – Doing a Strength, Weakness, Opportunities and Threat analysis of the (re)design, will help come up with associated risks of the design.

Expert Judgment – Leverage expertise of Subject Matter Experts within the project team or across stakeholders to identify the risks.

FMEA – Anticipating failure at each stage, its effect which in turn helps us to come up with potential mitigation plans.

 

Quantitative tools for Design Risk Analysis

Modelling Techniques – Develop models to capture Risks using critical inputs like probability of occurrence, severity levels, controls, vulnerabilities and come up with Risk Priority Numbers, Probability and impact matrix,        Expected monetary value analysis etc.,