I've had numerous conflicts of opinion with MSCs, schedulers, owners... and all but one were resolved successfully. By successfully, I mean that we both stated our positions, acknowledged that the other's position held merit, and most of the time, met somewhere in the middle. I believe that when you are valuable to a company, and that company is valuable to you, win some/lose some is the cost of doing/keeping business with them.
The one that wasn't resolved successfully... I was restricted from doing shops for a client ever again, because I had the nerve to go into labor three weeks early. It was a hard and fast labor, from start to finish- 5 hours, and yet I had the presence of mind to email the scheduler and say "Hey, I may not be able to make these shops today, I think I'm in labor." and then two hours later, emailed again saying "Yep, definitely in labor, please cancel these shops or reschedule 5 days out."
No response (I had my phone with me in the hospital and could still check email)... Instead, when I logged into the MSC site, the shops were off my log and I could no longer see any of them, anywhere in the US.
After numerous emails back and forth, the response I got was basically that I should have had the foresight to not schedule these shops if I knew I wasn't going to be able to complete them (I didn't, obviously) or that I should have performed the shops the day before (They had a three day window, and I went into labor on Day 2) since I knew I wouldn't be able to perform them the next day. (Again, I didn't know!)
I tried everything... I offered to shop the locations a day or two after getting out of the hospital, nope. I offered to do them for base fee (They had been heavily bonused) just to salvage the situation and retain the ability to do those shops in the future,... nope.
The emails rapidly devolved into accusations that I hadn't gone into labor, and was simply making excuses as to why I'd flaked, even though I emailed prior to "flaking." I responded to those emails with a photo of my hospital ID bracelet, showing the Maternity Ward and the date. I'd have sent a picture of myself in a hospital gown and hospital bed holding my newborn, if I thought it'd have done any good, but...no response to my first bit of proof, so I didn't bother.
Two years later, still can't do those shops. I felt it was handled poorly, and a bit unfairly, but I still do other shops for them.
Sometimes their reasons are highly unreasonable, but, in most situations where MSC and I have not seen eye to eye, I can understand their position and concede their point. My above example was not one of them... I still don't agree with their decision.
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Plan the work. Work the plan.