No question documenting projects and follow up service is a good thing.
Follow up service calls are easier to document because there isn't as many changes, but still have to be done. Conversely projects can be very heavily documented. I have found that different projects require different documentation.
Projects that have architect, general contractors, and sub contractors will have a minimal amount of documentation listed in the specifications of the project that have to be completed. And it doesn't matter how little or large your scope of the project is you will have to complete that list of requirements. So make sure that you account for that time when your quoting the job. I have had projects where the documentation was as long or longer to complete then the work being performed. It will save you time if you create templates for those items as well.
Another important thing is how the information is to be stored and accessed. It's so nice if all of the information can be stored in a single resource/application. And save you so much time and headache if that resource can be accessed while onsite with great ease.
The Project documentation are cardinal inorder to harmonize communication between the client and the service company. The docs formerlises the whole project process and lives most of the clients satisfied.
Without any docs client tend to be unsatisfied and sometimes even become difficult to pay for the service.
Therefore, such docs like the above template are very important to avoid disputes with clients.
I agree with the premise of good documentation. The document above combines the invoice with work order confirmation which might work for some businesses. In my experience asking the technician to know the tax rate and sell prices is not efficient use of their time. I recommend getting a signature for the scope of work performed, list parts/materials used and time onsite then have the office staff generate an invoice within 24 hours. If you cannot get a signature then a quick email follow up with this information works as well. Sometimes tacking down the POC onsite at the end of the work can be a waste of time.
Here are some of the fields we added on our work order:
We added person who authorized the work to be performed as well as point of contact onsite. These can be different and can cause confusion for the field tech and admin staff.
We added a field for follow up needed/parts on order/call complete. This let the end user know the status as well as what we needed to do behind the scenes to complete the work.
You also might want to check with your local insurance requirements however we used Onsite time/offsite time so we knew when the field technician was physically at a client's site. This was recommended by our insurance agent.