Hello
Ive had several companies. Multiple partners, one partner, sole proprietor and all they all have their pros and cons. Not in the elevator trade but my two cents. ( may start elevator one once my sons are older)

Multiple partners- hard to be on the same page usually always ends up in buyouts, backstabs etc
Make sure you have a shotgun clause in case things get ugly
(Also remember with multiple partners comes multiple wives. And they all think their hubby is working harder than you and deserve more than you)

Single partner- works well. When choosing Partner always team up with someone who works harder than you. Pretty straight forward and simple but imperative. Also have a shot gun clause

Sole proprietor.- everyone likes at first cause their the boss. I don't need anyone. More reward, more risk, more work. In that business I went on a cruise for my sisters wedding. Second day in at 5 am I get a text I quit from my main guy who knew exactly what was going on for everyone for the seven days I was gone. Nice

Sole proprietor with mini shares to keep interest
Works really well. Your still in control but to give 10-15-even 20 percent to right individuals works well because as bad as it is to say. They're married to you and will watch the spending and care more. Remember you still control the books etc so it's still under your control

Alternate advise. Hire a really good accountant. Don't do it yourself, mom, cousin etc. They may be cheaper but you get what you pay for. The books are the most important thing. Review daily weekly monthly etc. Don't wait for the end of the year oh no we lost money. Stay on it so you can react quick to control any bleeding.

When starting any business plan for the worst, hope for the best. If in a partnership write all sorts of clauses. When you're in the new honeymoon stage everyone will sign anything. That won't happen to us sure I'll sign.

Make sure you protect yourself. If married move everything into your wife's name or whoever. If business flops it's too late to move assets etc without looking like a crook. They can go back tears and say you knew you were sinking and bailed early and stole.

If it's not making money quit. Don't drag it out forever due to your ego. It only gets worse.

That's my take for what it's worth. I've made money,lost money but have made out fine. Right now I work on elevators and love it. I was thinking the elevator business would be good because all the maintenance money coming in on regular basis. What are the struggles of your maint contracts are written up decent. Guaranteed to make money? One outfit here in their maint contract they have the first right on mods to beat everyone's price.

I'd love to hear more about the money side in the elevator trade