About 35 years in the past, I used to be despatched from the U.Ok. to Canada to troubleshoot a manufacturing plant for the primary time throughout my fledgling software program engineering profession. My job was to finish commissioning of a batch processing plant whose management system consisted virtually solely of a single DEC LSI-11 (PDP-11/03) with much less reminiscence than you’d now discover in an affordable watch, working a long-forgotten multitasking working system, and deploying a modified model of the BASIC language.
By the point I arrived, the preliminary commissioning effort was full, and the plant had a full manufacturing schedule to work round. Though issues with the management system meant working fairly slowly, the plant wanted to offer animal feed for the chilly Canadian winter months. My alternatives to deal with the problems on the dwell system carried appreciable strain. It was a uncommon event when a slot was given to me to truly do one thing.
The client’s ever-patient and supportive engineering staff helped me lash up a 240-V provide for my U.Ok. spec improvement machine, and I spent hours engaged on options offline, ready for my window of alternative to strive them on-line. There have been frequent ups and downs alongside the way in which, and one particularly memorable look from the client in response to a menu possibility whose solely perform was to show the message “But to be written”!
Do you’ve got a memorable expertise fixing an engineering downside at work or in your spare time? Tell us your Tale.
The manufacturing scheduler software program was proven-in-use on numerous earlier methods. It was designed to prepared the manufacturing plant to make the subsequent scheduled merchandise, make sure that the bagging machines had been readied, and monitor manufacturing earlier than beginning the cycle once more.
However in a single explicit configuration, it displayed a really elusive bug that occurred as soon as each few weeks. Provided that it was a medicated feed to deal with animals starting from chickens to racehorses, the potential for catastrophe and litigation was all too actual.
Many hours had been burned looking for the timing situation. It couldn’t be provoked on a simulated system and left no hint when it raised its head on the manufacturing system, however one thing needed to be completed.
The answer was as efficient because it was ugly. Instantly earlier than a brand new manufacturing run started, I added a closing test to make sure that the scheduler entry, the allotted manufacturing batch, and the packaging all matched. If it didn’t, the scheduler was pressured to strive once more till it did. Pragmatic? Actually, and the client was very completely happy that their plant might now be trusted. Greatest follow? Hardly. Would you need flight management software program written like that? Positively not.
Nowadays, I work with practical security, cybersecurity, and coding requirements, and it’s straightforward to neglect these painful overheads. No, actually, they assist us write software program that works correctly. So, if I begin to wonder if practical security and safety requirements are actually needed, I solely must suppose again to a really chilly Canadian winter to search out my reply.
Mark Pitchford, technical specialist with LDRA Software Technology, has labored with improvement groups trying to obtain compliant software program improvement in security and safety crucial environments, working with requirements similar to DO-178, IEC 61508, ISO 26262, IIRA and RAMI 4.0.