Software Lifespan

How long should our software last? I’m sure that there are software packages out there that were built decades ago, but I’m talking about packages still being actively updated and sold. Personally, I figure if I get 5-7 years out of system before a major refactor of some part of it, then I’m doing great. Even if you continuously refactor, you will eventually get to the point where the cost of new features in legacy code become prohibitive. Shortcuts are taken or information is lost, and the result is code that is tough to maintain and update.
How long do you think code lasts before it’s too expensive to update?

The recent Mars Lander story made me think about this. Talk about a huge pat on the back to those NASA engineers. They built a system meant to last 90 days that ended up lasting almost 2000 days. Who knows? If it can survive the Martian winter, it may be able to keep going. The Devil’s Advocate in me might say that they grossly over-engineered it, but mostly I’m supremely impressed the a group of engineers built a machine that survived in a very hostile environment for 5+ years.







6 responses to “Software Lifespan”

  1. Dave Avatar

    Great article. Thanks. My only comment about comparing software engineering to civil engineering is that an office building is not soon asked to be a hockey stadium. It is rare that a software product knows precisely what it will be when it grows up. That said, I’m all for making software that lasts forever. I’m a little jaded by recent startup products that evolved so much that the foundation became wobbly.

  2. Tweets that mention Software Lifespan » Big Dave’s Blog -- Avatar

    […] This post was mentioned on Twitter by Betsy , Dave. Dave said: New blog post: Software Lifespan […]

  3. albel86 Avatar

    Надо будет в скором времени на адалт перейти: прибыльный бизнес… Везде эротика уже… Печально, но ничего не поделаешь((

  4. Bruce Avatar

    […] This post was mentioned on Twitter by Betsy , Dave. Dave said: New blog post: Software Lifespan […]

  5. Dave Avatar
    It looks like at least one of the landers is no longer with us. It was still a great run for them.

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