A completed job can give you useful information for the next estimate. The question is whether the labour and materials you expected match what the work actually used.
Start with one finished job
Compare estimated hours with recorded time, materials allowed with purchases, and any return visits or additional work. Decide consistently where travel and other direct costs belong.
Check how costs are recorded
A receipt scan can help collect information, but it still needs the correct job and amount. Time records need the same attention. Incomplete inputs can make a neat report misleading.
Know what the margin includes
Revenue less recorded job costs is not automatically the business's final net profit. Confirm how overhead, unallocated time and other expenses are treated before using the figure to judge pricing.
Your current software may support some of this already. Which part is hardest to see now: actual hours, material use or the extra visits?