How to Justify Scrum to Senior Management

Often many people say that it is difficult to justify Scrum to the senior management. I think there are two alternative approaches you can take to justify Scrum:
If the senior management is willing to listen , you can tell them about the following scrum benefits:

• None of the software development methodologies can predict the exact date of software completion with exact amount of resources. In most cases where inputs and outputs are not well defined, empirical process control model is the only workable model for software development. Read chapter 5, Agile Software Development with Scrum.

• Prioritized product backlog ensures that 80% of the business value is delivered in 20% of the time. Read Appendix D, Agile Project Management With Scrum.

• Product gets a legitimate chance to change their product based on sprint demos. There is no need to file a change request and charge more in case of a fixed bid and/or fixed date contracts. Scrum being a transparent process, it gives more visibility to the management than waterfall, which provides no visibility till the time the product is finally released.
  

• Once Scrum is in place, it is possible to estimate release dates roughly based on historical velocity data. In fact, you will be able to predict release dates of the current project with 80% probability after 20% of the work is done - within 3 to 5 sprints based on the project size.

• Scrum exposes problems earlier, there by giving a chance for management to cancel the project if necessary.

• If you are a high maturity company, then using Scrum will improve productivity and performance significantly as concluded by Jeff Sutherlands's paper - Scrum and CMMI Level 5: The Magic Potion for Code Warriors
  

If the senior management is not willing to listen, you have no choice but to do the analysis first and give them a date. You may not be able to score with a management not willing to listen to new ideas.