Customers often ask me the usefulness of a continuous machine parameters monitoring. After all, it takes just a few days, or weeks, to understand where wastes are and how to improve plant productivity.
Well, it is true that collecting data for a few days or weeks permits you to identify the most important critical points and also get cost savings and significant improvements in the production process, but I am fully convinced that changes in the system can only be caught by continuous monitoring.
I tell you this episode that can help us reflecting about the hidden dynamics of machinery.
A client of mine has a few identical machines that require a bit of time before they are ready to be used because they have to reach certain operating temperatures. When machines are ready, an indicator light turns on and workers start their job.
Workers have learned that these machines are ready after 15 minutes so, in the morning they turn the machines on and then they have their well-deserved 15-minute coffee break after which they go back to their machines and they finally start to work. The so organized system has worked for years, but a year ago, due to a machine failure, an electronic card has been changed and after that the machine promptly got back to work. A few months ago, after having met my customer, I proposed him to repeat the machine parameters monitoring and I noticed that the fixed machine has now the following heating diagram.
Most likely the new electronic board has the best performing PID or an optimized software. No one had ever noticed it in the company because they had assumed that machines could not change their behavior. Let us assume that you can save five minutes of downtime for each machine, which costs about 2000 €/hour. Needless to say that my client has updated all the machines with new cards.
This incident taught me three things:
The first: production process, especially if composed of machines that work interconnected among them, has a complexity hardly controllable with the intuition and experience. Actually the past experience sometimes makes us unable to see changings in things, in people, as well as in machines, and we lose the opportunity to improve the way we work.
The second: we, engineers, are used to think that machines can only downgrade their performance as the time goes by, and we forget that machines can also be improved. Especially the equipment built some years ago, with mechanics that make many of the latest generation systems envious, can greatly improve their performance and their quality of work, if updated with electronics, sensors and software that today are available for all budgets.
The third: the continuous monitoring, which is the basis for trend analysis and predictive maintenance, allows us to adapt quickly and cost-free the usage of equipment at the right.