There was a question on the NWLean email list about suggestions, in the context of The Idea Generator: Quick and Easy Kaizen, 
“My question is this; is the 2 suggestions per month per employee forced? Meaning do I require each worker to sumit their ideas or do I suggest that they do?”
Thankfully, Norman Bodek chimed in and pointed out this is never coercive. Lean leaders only fall back on positional authority and telling people what to do as a last resort. Hopefully it starts seeming silly to people to use one concept (getting employee input) via a non-Lean approach (mandating things).
The question continued:
If the answer is that I suggest they do, then what is the next approach I take if I have very little participation?
I think cases like this provide great opportunities to ask “why?” Why are employees not participating? The answers will vary depending on your environment, but it's always a good thing to ask “why?” instead of redoubling the mandate efforts.
Mark Graban
Mark Graban is an internationally-recognized consultant, author, and professional speaker who has worked in healthcare, manufacturing, and startups. His latest book is Measures of Success: React Less, Lead Better, Improve More. He is author of the Shingo Award-winning books Lean Hospitals and Healthcare Kaizen, as well as The Executive Guide to Healthcare Kaizen. He also published the anthology Practicing Lean that benefits the Louise H. Batz Patient Safety Foundation, where Mark is a board member. Mark is also a Senior Advisor to the technology company KaiNexus.