A single source of truth for every job
Most scaffolding businesses we meet are running every job through three or four places at once — a WhatsApp group with the lads, a Dropbox folder for drawings, a clipboard in the van, and the office trying to chase everyone for hours at the end of the week. The first system you need is a single place where every live job sits: customer, address, contract value, who's on it today, when it goes up, when it comes down, what's outstanding.
Without it, your office manager is the system — which means when she's off, the wheels come off. Once a job lives in one place, every other system you build hangs off it cleanly.