Building plans often specify the overall measurements for kitchen and bathroom bench tops and cabinets.
But you can't rely on them for your actual working dimensions.
The only sure way to be sure that your units are going to fit properly and finish professionally is to physically check all the relevant measurements on site.
Does the floor plan shown in the previous photo look familiar? These are the layout details that the installer recorded before he physically started the job.
Ask your work supervisor whether you can have a look at examples of sketches that your installers have done on the job. Have a look at the measurements noted and the sorts of details recorded. If there are any abbreviations you don't understand, find out what they mean.