I've had the opportunity to design and run hundreds of ideation events on all types of topics for a variety of clients, both big and small. One constant in all of this is what I coin the "Cure World Hunger" topic.
These types of topics are generally very vague and very high level, like curing world hunger. For whatever reason, most clients always start at this level of abstraction; especially when it comes to "Cost Cutting/Saving" topics.
Some would argue a wide-open and unrestrictive topic is a good thing. It lets the audience explore boundaries that would not normally be looked at or considered; and that's probably true.
However, lets explore a typical cost event. First, for simplicity purposes, let’s assume outside of wages, your highest expense category is business travel and that the two account for 60% and 25% of expenses, respectively. All other business expenses combined account for the remaining 15%.
In a typical "Cure World Hunger" cost-cutting campaign you'll get plenty of ideas around reducing salaries, especially management (which won't happen - *smile*) and staying in cheaper hotels, booking flights early, buy supplies at Big Box, etc. All typical and a waste of time – you don't need an idea management system that can reach thousands of employees to tell you that. But this is more the norm than you might think; even after counsel to avoid such exercises.
To further compound the issues/problems with this approach, the ideas that generally get chosen are those that add additional project burden onto teams that are already strapped with delivering other projects. These ideas typically distract from the teams’ goals; thus the ideas usually get shelved and never implemented.
A better approach is to specifically identify a cost driver and the desired outcome; and an even better, identify a driver that will help a team or teams meet their current objectives. Then run an ideation around this specific driver and outcome. There is still plenty of room to be creative and find unique solutions.
What's not obvious sometimes is that even a 1% cost savings in a particular part of the business can means millions in additional revenue, or it can free up significant resources to be use elsewhere. If aligned with current objectives you also have resources ready and willing to execute and deliver that value.
Curing World Hunger is a worthy goal, but doing so city by city or town by town is likely a more effective approach.