Pro-tips are designed to help you stand out as an automation professional. Remember: learning from someone else's mistakes is more pleasant than learning from your own.
Just as it is easy to add alarms, it is easy to say "we should automate process X." Similarly, you could say "we need more people to do Y." Striking a balance in a factory, treatment plant or power generation facility is always going to be hard. Still, it is not impossible.
You need an understanding of what a person is and what a machine is.
Your control system should do routine, redundant work. Machines are good at that. Computers are good at that. They should throw good alarms when something non-standard comes along.
Operators are the brainpower of an automation system. They need to be checking setpoints, taking gear out of service for preventative maintenance, documenting critical equipment and being ready for alarms. When something is outside of the parameters for the control system, they need to step in. If you have a (somewhat) relaxed operational staff, you are probably doing something right! You want people to be free to step in and fix alarms. (You still need to keep on top of PMs.)
Managers should be determining set points, scheduling down-time for repairs and getting involved in equipment upgrades. They should not be baby-sitting senior staff on how to do basic tasks. (Even mid-grade staff should be replaced if they cannot perform basic job functions.)
An overly automated plant will be impossible to troubleshoot, or near enough to scare anyone. I have seen plants with four PLCs that need to work in tandem for a backwash. Troubleshooting that system was a nightmare.
A more recent treatment plant was at the other end of the spectrum, which had a "read only" SCADA system. They had no central controls, two campuses that spanned a few kilometers and had operators manually checking tank levels every hour. (I will omit names to spare the guilty.) The plant management seem surprised that PMs are missed. How would the operators do PMs if they need to walk / drive from building to building just to hand-record tank levels? Why bother having a SCADA system at this point?
For reference, my current employer has employees walk around sites once per shift. Also, if you miss something big, they discipline and remove you. Hence the trust... If you cannot trust someone, you should not keep them.
Let's do the math. Assume the plant has...
15 tanks
The probes each cost $2,000, plus $1,500 to wire
A sum total of $10,000 to program all of them into SCADA.
The total price is $62,500.
Now, let's talk about the return. Assume the plant has...
Four operators per shift, three shifts a day.
They make $20/hour
Half their shift is walking the plant to manually check and write down levels.
If you get half of two people's time back per shift and include $0 of overhead, you are "saving" the company $960/day. You have a full pay-back in three months. Not automating that is an incredible oversight.
The best part: you would not need to fire anyone! Why bother? The site needs maintenance. Have these people who were doing machine work do work for people. Have them maintain something! Sure, you do not get a quick ROI, but you suddenly are fixing long term issues.
(Note: some of these assumptions are from former staff. They are not as ridiculous as you would hope.)
Let us do some further counter arguments.
Q1: How do we know the staff did walk their rounds?
A1: You do not. However, if something is missed, you need to follow your HR's discipline guide.
Q2: How will we know if a sensor fails?
A2: This is a better question! You need to pick the right sensor and set up your controls accordingly! Perhaps you need a failure contact on the sensor? Have you standardized on 4-20 mA signals, with your instrument set to show < 4mA when it fails?
Q3: What if SCADA goes down?
A3: This is an excellent question! You do want to keep the knowledge of how to do the minimum manually and have systems in place to run when automation goes down.
Q4: We do not have money.
A4: This pays for itself. Write an official business case and kick it up the food chain.
Q5: Why change something that has always been this way?
A5: It may have worked in the past, but that should not stop us from improving whenever we can.
I am going on a tangent again. Think before you automate. (And really, really think before you choose to not automate extremely tedious and repetitive tasks.)
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