When asked about how to convince management about Scrum I basically go around about risk reduction and ROI, since these are the main things people at the higher management level care about.
The #1 reason for project failure according to the CHAOS research is lack of customer involvement. So why not use a process that eliminates that risk?
Using a incremental process significantly reduces the risk of wasting money on something that’s not going to be useful, because the customer helps steer the product development in the right direction through series of planned feedback cycles.
Also, with a incremental process you start delivering something in a much shorter time than when using a waterfall approach, which effectively increases the ROI (return on investment), since the customer starts benefiting from the product after one or two months, instead of waiting 6 to 12 months in a typical waterfall project.
You can also mention improved customer satisfaction, team self-improvement and self-management, which reduces the administrative overhead, improved employee satisfaction and a bunch of other more intangible advantages.
