The quote wins the job, and most of the time speed is what decides it. When dimensions, material and photographs come in structured, the price goes out the same day rather than at the weekend — and in this trade replying first wins remarkably often.
Changes on site are the rule, not the exception, and they're the biggest single cause of lost margin. Recording every change against the job, with a date and an added cost, is the difference between a variation you can invoice and a conversation you can't.
The fitting date depends on the steel. When supplier lead times sit on the job, nobody promises an installation that a stockholder can still move by a fortnight.