Overview
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FMEDA objects are most commonly mapped to design instances. For parts and subparts instance boundaries are always sufficient, but for FM mapping there are cases where module boundaries don’t exist or don’t provide the right level of precision:
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When a leaf instance doesn’t provide enough resolution – as created by the designer.
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When a leaf instance doesn’t provide enough resolution – when created by synthesis by flattening a design hierarchy.
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When an instance is not a leaf, but more resolution is needed for its own (sparse) logic (less common).
In such cases the safety engineer is interested in performing an analysis on design instances to extract elementary functions from the design logic. These are extracted based on selecting points on the design when server as functionality end points or design constraint, and then performing a “cone of logic” analysis.
Safety Planner GUI | Elementary Function
UX and UI for the elementary function of the Safety Planner, a web application by Cadence. The app is based on FMEDA technique, and is designed to plan, run and analyze chip verification for the automotive industry. In this project, our goal was to create an efficient work methodology by defining and optimizing user flows.
The elementary function is used to reduce errors that might affect the calculation of the safety indices, by accurately isolating failure mode root causes.
Teamwork
I worked on this project with the lead Product Designer, Shirley Kimchi, and collaborated with our US-based UX Manager, our Italy-based Solutions Manager, and a team of developers based in Israel. Our goal was to create an efficient work methodology by defining and optimizing user flows. My main responsibilities were characterizing all of the pages and modules and designing the final UI.
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Overview
FMEDA objects are commonly mapped to design instances. For parts and subparts, the instance boundaries are always sufficient - but for failure mode mapping, occasionally the module boundaries don’t exist or don’t provide the right level of precision. In such cases, the safety engineer must perform an analysis of design instances, to extract the elementary functions from the design logic. This process is completed by adding endpoints and design constraints, and then performing a cone of logic analysis.
Whiteboard Flow
We started the characterization process by brainstorming and mapping the entire feature flow on a whiteboard. This was a challenging but fascinating stage, in which we translated the requirements document into a basic specification of the user flow, including the main flow, the secondary flow and a review of all possible use cases and pain points.
Challenges - Flip Flop Search
Due to the complexity of the system, we split the feature into several smaller stages, and reviewed every single detail separately. One of the most challenging features I designed was the flip flop search - a function that had to be accessible from the design hierarchy itself, because the users were using it in two distinct flows.
User Interface Design
Some of the final User Interface design screens.
Following extensive research regarding the users’ workflow, I concluded that displaying the full path would harm usability - the path may be extremely long, extend beyond the boundaries of the modal, and force the user to scroll and miss the relevant flip-flops. I decided to split the path into two columns, and display the flip-flops searched by the user as static elements in the first column. This design choice allowed the users to quickly and effortlessly scan their search results and spot the relevant items.
Feedback
“Yesterday, I have performed a very complex Elementary Functions generation on TI test case. I have experimented that the GUI for the setup of the End-Points was very usable. The Search function works very well and allow to select or deselect (when we need) the FFs and pins in very simple way.
In addition, in term of time, I have performed complex modifications of the End-Points selection (after analysis of the extraction results) in 10 minutes so I am really impressed from the GUI usability. It is very simple to renegotiate the safety strategy and this is a big add value respect to other tools that I have used in the past".
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Thanks a lot for your excellent work!
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Kind regards,
Antonino Armato, Sr Principal Solution Engineer