Many book I read, the perspective & objective related with maintenance is ROI. I would like to know, how to measure ROI for maintenance department?

Thank you.

This is a basic article on ROI:
http://en.wikipedia.org/wiki/Return_on_Investment

So, ROI is Returns obtained vs Investment

Management can easily identify investment made (just look at the budget reports), the trick part is identify the returns obtained due to the use of that investment.

* Increase in Uptime translated to $$$?
* Reduced operating costs?
* Reduced energy costs?
* Other Costs avoided?

You should try to go to a seminar or conference that focuses on the ROI of maintenance. I checked Noria's website (www.noria.com) to see if they have any partners in your part of the world, and indeed they do. In fact, there is a seminar called "Strategic Plant Reliability Management" on April 26 & 27th in Malyasia that is being conducted by a Noria franchise partner. With a name like that, I would think a good portion of the seminar would be devoted to ROI issues.

There is a report on ROI related to CMMS implementationd and hence maintenance on this page, http://www.pemms.co.uk/cmms_ROI.htm. Examples are included, which may be useful to you.