How important do you think andon is? I think it is extremely important.
Kaizen workshop teams usually build great standard work or reliable methods. I see them eliminate waste, create detailed implementation communication schedules, and ensure the auditing plan will give something to measure in PDCA. Andon is not always added.
Andon must be built into a new or updated process to make it sustain. If there is no mechanism to stop and fix errors before they are passed to the next step, quality will suffer. Waiting for the error to show up in the audit or a visual management system may be too late.
Workshop teams usually have tons of confidence their new process will be flawless because they thought it out thoroughly. Challenge and remind them the importance of andon.
I would like to recommend two articles: Fixed Position Stop Systemby Jon Miller at Gemba Panta Rei and Parenting Tips from Toyotaby Craig Woll at Evolving Excellence
Improve With Me 
Pingback: Be An Andon Referee « Pass The Buck