The Difference Between "Sneak Circuit Analysis" and IDA's Sneak Analysis Approach
Sneak Circuit Analysis, or SCA was developed in the late 1960's for NASA to verify the integrity and functionality of their designs. Electronic control systems at this time were designed with relays, vacuum tubes, diodes and resistors. They did not contain Integrated Circuits, microprocessors or software like modern systems. Isolating each function from the other functions was a challange to these early systems because current could inadvertently flow through an unintended path causing false indications, glitches, unintentional outputs, etc. especially when interacting with the equipment throughout it's operational scenarios. Sneak Circuit Analysis was a useful tool to discover all these unintentional circuit paths and assisted in devising solutions to isolate each function. However, as technology advanced, the tools for Sneak Circuit Analysis had to also advance.

With the relay/diode logic, Sneak Circuit Analysis used search programs initially developed to identify all the current paths through a system. These programs allowed the Analyst to identify topological patterns of current flow and the Sneak Clues were simple derivations from these patterns. Sneak Circuit Analysis is this electrical, topological, examination of the electronics and is limited to simple logic, very few Integrated Circuits, and cannot integrate in software code. Sneak Circuit Analysis using a search program does not analyze the functions of the system, just the current paths.

Sneak Analysis is the next higher level of Sneak Circuit Analysis. In the 1970's, it was recognized that searching current paths did not work well for analysis of circuitry that contained Integrated Circuits, analog electronics, programmable devices such as PALs and ASICs, and microprocessors that execute software code. Sneak Analysis was re-developed to capture the functional characteristics of the system as well as the current paths. SCA was developed under a government contract and the methodology is public domain. However, Sneak Analysis has developed well beyond what was initially paid-for by the government. IDA continues to refine the Sneak Analysis methodology by automating many of the processes, adapting the analysis to fit new technology, and updating the clue list which now contains more than 30 years of experience in Sneak Analysis.

Sneak Analysis far exceeds the coverage of Sneak Circuit Analysis. Sneak Analysis can locate problems in both hardware and software using any technology. The Sneak Analysis tools used by IDA, can integrate several analyses such as Fault Trees, Failure Mode and Effects Analysis (FMEA), Reliability, etc. into a single analysis saving time and project expenses.