Whats the best way to go about upgrading a project with major design changes…in terms of project files (I guess)? I recently moved my website from ASP.NET to ASP.NET MVC and it was obvious that changes were so major it required a complete rewrite. Now I am preparing to move it to MVC 2, to take advantage of more features of the new framework, and again I am running into some road blocks which are moving me to do basically another complete rewrite. I would of course like to avoid this if possible because the site has grown quite large over time. I did do a good job of documenting the design decisions during the last rewrite however, and it would only take a few weeks to do another rewrite.
When do you need to make the decision to scrap the current project and bring everything up to the new technologies? If you create a new project file, whats the best way to handle migrating over the stuff that doesn’t need to change from the old project?
You do a rewrite when the cost of maintaining and extending the current codebase outweighs the cost of debugging a new one.
How you determine the costs, however, is highly subjective.