Kaizen events fail when the team arrives Monday morning and spends the first day arguing about scope. The charter prevents this. It locks in agreement on what you're fixing, what success looks like, who's doing it, and what's off limits β before the clock starts. The sponsor signs off. The team can now spend 100% of event time improving, not debating.
Scope is the #1 killer of kaizen events. If you can't describe the scope in one sentence, it's too big. Split it into two events. A focused event that achieves its goal builds momentum. An ambitious event that fails to finish destroys trust in the process.