The major part of IT project costs are not related to the initial setup!
Operations, maintenance, updates, bugfixes, application administration, backup and disaster recovery exercises make up the majority costs and should not be neglected in the initial planning.
Actually, the more a project is meant to be temporary, the longer it will run and the more it will cost in the end.
To underline my personal beliefs in this matter I found the following links on the Internet, I am sure that with some time on Google you can find even more:
- Distribution of Cost Over the Application Lifecycle - A Multi-Case Study
This study show very nicely how up 60-90% of total project costs over 5 years are recurring costs (Figure 3).
- Frequently Asked Questions about TCO from Federal Electronics Challange
This is also a golden opportunity to include the original requester in the discussion about TCO and about who will actually spend their time on the follow-up tasks.