So..... How much are you making on each that job you are working on?
Easy way to check is by using the margins button in the job BEFORE you invoice.
Simple really - if you know you aren't making the correct margin for each part you can increase it before invoicing.
This is also simple - in the Job, click on margins:
By default this will show by Posting type first, from here you can choose all postings:
And we notice that one part only has a margin of 8.3%.
You now have the opportunity to increase it.