While deploying a SharePoint project, the Visual Studio executes a series of deployment steps in a specific order. Visual Studio encompasses numerous built-in deployment steps, also lets you can also create your own.
You can create a custom deployment step to upgrade solutions on a server that's operating SharePoint.
Visual Studio includes built-in deployment steps for many tasks, such as retracting or appending solutions, but it will not include a deployment step for upgrading solutions. By default, whenever you deploy a SharePoint solution, the Visual Studio first retracts the solution
Microsoft provides two built-in migration options and present major limitations to those approaches, including lack of version to version flexibility, controlled testing capabilities, no steady or partial migrations, and no options to migrate to SharePoint Online or Office 365. Using a product such as Metalogix Migration Manager for SharePoint can greatly improve this situation and unbound the organizations to securely migrate or upgrade their document management environments.