Ginger Grant argues in favor of the project deployment model in SSIS:
Prior to SQL Server 2012, there was no project deployment. SSIS code was all deployed as packages. These packages could be stored within MSDB or they could be stored and run from the file system. In disorganized places like the one where I worked, they were deployed in both. Assuming nothing much changed since I left, they have all versions of SQL Server which were released prior to the day the new IT Director started in 2012. There was DTS on SQL Server 97, 2000 and SSIS on 2005, 2008 and 2008 R2. No reason to upgrade anything which still worked was their motto. When space was a problem, one could always go build another server. I think the LAN administrator was happiest when he was able to justify building a new server as he could spend hours shopping for parts on the internet and building the latest server.
I believe that, in the business, we call this a “nightmare scenario.” Read on for ways in which a project model would help.