Very good post but unfortunately, sometimes bad SW lasts a long time too. I was recently called down to our proto line to help out with a 20 year old machine vi

Very good post but unfortunately, sometimes bad SW lasts a long time too. I was recently called down to our proto line to help out with a 20 year old machine vision app. All the HW was obsolete and the SW was unmaintainable. I know that for sure because I wrote it. The whole manufacturing line was shipped overseas a couple times and returned to us a little while ago but the engineers just kept it running as-is. In this case the cameras, framegrabbers and light sources were all still working, which is impressive. However, SW is closed source and the licenses can't be renewed, in the end that's what's making it unmaintainable.