Continuous Improvement vs. Continual Improvement

Most organizations implementing lean principles today do not in fact practice “continuous improvement”. What they practice would be better termed “continual improvement”. The distinction between continual improvement and continuous improvement is a fine but important one. Continuous means “without interruption” while continual means “frequent, repeated or seemingly without interruption”. Continuous is “go go go…” while continual is “start stop start stop start…” Continual improvement is far better than no improvement at all but it is far from world class and not the aim of lean.
In practical terms you can think of an alarm clock ringing and ringing without interruption as continuously ringing. Hitting the snooze button of a ringing alarm clock only to have it start ringing again later that morning and then hitting the snooze button again, would be an example of a continually ringing alarm clock. If the alarm clock did not go off at all and we could sleep in that may be ideal, just as it may be good to take a break from kaizen on some days so that ideas and energies can be refreshed. Neither continuous improvement nor continual improvement implies that we spend every waking (no sleeping) moment doing kaizen.
For some reason many organizations implement lean from the middle of the organization outwards. One possible reason is that the sponsorship from lean is at middle or senior management rather than the very top of the organization. This creates the need to implement lean as a series of projects led by lean experts rather than a transformation led by a fully engaged leadership and management team. These projects may be very successful. Often they are designed to demonstrate how lean systems will deliver specific desired business results. But projects have scopes and boundaries and by definition are discrete or at best continual and not continuous activities.
Kaizen events break projects down into a more frequent and repetitive series of rapid improvement activities. I know many good companies who have “continuously” been running kaizen events month after month for over a decade. But I am skeptical that relying chiefly on kaizen events represents true continuous improvement. Combined with projects that look across an entire site or value stream, kaizen event-driven lean implementation can greatly accelerate change. The glue that holds these kaizen activities and events together and makes continuous improvement possible is the practice of kaizen as part of daily management.
Kaizen in daily management includes everything from managers finding teaching moments with their subordinates as they make their walks through the gemba, to team leaders helping team members develop complaints into problem statements into root cause analysis exercises and implemented suggestions, to the engineer or manager running to the red andon lamp and making a rapid response to problems that have been identified and escalated.
In other words continuous improvement is not about the exciting, high-energy kaizen events and high-impact lean implementation projects but all about the sometimes boring grind that gets us through the day. The good news is that there’s plenty of it for all of us. If that doesn’t get you up in the morning there’s always continual improvement for you.

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