Can you help me please?

IT projects have a long (relatively) history of burning though large amounts of money, being horrendously late and when something finally gets delivered it's not what anybody ever really wanted!

There's been numerous attempts to solve this problem... From trying to be more detailed/better planning/contractual lockdowns to methodologies that roughly fall under the Agile umbrella such as Scrum, Kanban and other variations.

Large construction projects have bit of bit of a chequered history too... Crossrail and Wembley Stadium are not great examples of how construction are doing things right... However some very large complex projects like Heathrow Terminal 5 have been more successful (despite some issues!)..... I've been involved on construction projects which have been won on a 2% profit margin and delivered... We wouldn't dare attempt to bid for an IT project at a fixed price with a 2% margin!

I am not going to attempt to make any link between construction projects and IT projects... This has been done all too often and is heavily flawed, however there's are still things we can borrow..... Over several decades the construction industry has built up a database of projects, these serve as reference points where past projects have been costed based on size, complexity, location, etc, etc - Over the last few decades this has been used as part of the estimation process within construction projects and is one of the reasons why we see less and less severe project overruns within that industry!

OK! Back to IT, There is a surprising lack of useful, easily available data in existence that shows the success of IT projects measured against estimations/actuals (In engineering) let alone predicted ROI against ROI - This data rarely exists within companies (except for peoples gut feel) let alone as open source data that can be shared so we can all learn!