Virtually everything related to the business core of the company I work for relies on some item numbers being generated sequentially. Unfortunately, a long time ago these item numbers were defined as a fixed point with no decimals and they are running out of possible numbers.
Of course, some departments were smart enough to define these as at least 32bit integers and can easily accommodate the increase.
I am currently working for various data warehouse satellite applications and I know that the data warehouse itself must accommodate the change. Data warehouse developers were asked to estimate the change and they provided a very large effort (about 800 person-days). This information is provided within an internal platform along with the estimations for all involved business units.
Having worked on an application to provide automatic testing for data warehouse I know what they must change (e.g. drop indexes, statistics, alter the column, recreate indexes, recreate statistics, update some proprietary metadata for all involved tables, check and change temporary tables precision in some scripts, test that everything still works etc.) and I think their effort estimation is very large.
To answer some issues in comments/existing answers: I can back up this with facts like number of tables affected, number of metadata files affected, as I am aware that without this there is no point in discussing this issue.
Also, there was an e-mail explaining why the effort, as one of the product owners also wondered about this. The effort is mainly proportional to the number of affected objects (tables and reports) and contains no reference to obscure components or a big reserve for the "unknown".
Why does it matter?
Since we belong to the same business unit and its budget is limited, if this effort is approved, our team will receive a small budget for next financial year. This is important as we are struggling to have an extra member to cover the workload.
Only two persons I can speak to come into my mind:
- people manager - very loosely connected to data warehouse people and also very busy
- the product owner for one of the projects we are working on - I have a very good relationship with him, but he is also people manager for some of the persons involved in the estimation, so it looks like a "conflict of interest"
Question: How should I proceed if I suspect about a project being grossly overestimated? (and this affects me and my team)