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  • 1.  Software Design Specification (SDS)

    This message was posted by a user wishing to remain anonymous
    Posted 17-Mar-2020 09:33
    This message was posted by a user wishing to remain anonymous

    Dear RAPS members,

    I need help with Software Design Specification (SDS) documentation. The SDS lists a design limitation in the document, but I have not come across an SDS where a design limitation is stated.

    Is it ok to state design limitation in SDS? If yes, what other information should be listed with the limitation.Please advise.


  • 2.  RE: Software Design Specification (SDS)

    Posted 18-Mar-2020 10:41
    The topic you are asking about is quite broad without having specific example or device provided.  The Software Design Specification (SDS) is the "low level" specifications for software basic operating functions such as algorithms, calculations, file I/O, etc.  A design limitation would be a simple example where a software could not say alert the user if a certain sequence of events happen or design limitations on calculations or results being provided.  You would definitely want to state any design limitations in the SDS ... and maybe even the SRS.  There is some information out there related to IEC 62304 about limitations and description of the SDS requirements.

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    Richard Vincins RAC
    Vice President Global Regulatory Affairs
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  • 3.  RE: Software Design Specification (SDS)

    This message was posted by a user wishing to remain anonymous
    Posted 25-Mar-2022 09:25
    This message was posted by a user wishing to remain anonymous

    Hi Richard,

    In continuation to your response on SDS, What level of details need to be captured in the SDS document for FDA submission?

    The guidance document says that "The Software Design Specification (SDS) describes the implementation of the requirements for the software. In terms of the relationship between the SRS and the SDS, the SRS describes what the Software Device will do and the SDS describes how the requirements in the SRS are implemented".

    While it is understood the intent of the SDS, what kind of information (in terms of depth) does FDA expect from the SDS document for a moderate risk software? Shall we just discuss in detail on Item level of software components and their interfaces (with reference to Architecture)? This way we can have a traceability between SRS & Architecture components.

    Alternatively, Shall we take each software requirement (SRS) and decompose it into several SDSs and list them in the document? This way we can have a traceability between SRS & SDS.

    I am little confused on this aspect.

    Appreciate your expert advice.


  • 4.  RE: Software Design Specification (SDS)

    Posted 28-Mar-2022 10:07
    Hello Anon,

    As I indicated it is a little difficult to describe about the SRS and SDS without knowing the device.  The questions you are asking are very involved, which are specific to a product.  Might suggest seeking some expert advice on your software product.

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    Richard Vincins ASQ-CQA, MTOPRA, RAC
    Vice President Global Regulatory Affairs
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