A professional electrical software will help you at several levels:
First, it will make you save a lot of time.
You will start with importing your floor plan and begin to insert equipment in a few seconds. A component database will help you select the brand and part numbers you daily use.
Also, once equipment has been positioned, the software will automatically generate single-line diagrams and bill of materials (BOM)
Then, you will create highly professional-looking electrical documentation with less errors. The software package will make sure, at every step, that your design is compliant with local or international standards.
Hence, modifications will be made easy. If you need to produce a similar design for another customer, you will simply need to re-use your project and amend it.