Well, it depends on what you mean by “incrementally.” Lean, or continuous improvement after all, is nothing but a series of small gains that add up to big results. From this perspective implementing lean could be said to be all incremental. If what you are really asking is “Can’t I go at this slowly and carefully to avoid any mistakes?” then the answer is no, you cannot - at least not if you expect to show good results.
Implementing lean is nothing if not a constant series of ‘leaps of faith’ into the unknown. The moment that machines have to be moved or the office rearranged into a better flow, the question of "But what if it doesn’t work?" will always be there. The fact that you thought this through quickly, say during a one-week kaizen, only adds to the anxiety. But you have to take the leap.
Moving machines on the first day of kaizen is a leap of faith to be sure: you can damage them, waste time hooking them back up, risk customer service in a number of ways, and push the operators way out of their comfort zone. But if you don’t move them you won’t learn anything and you won’t improve. Dramatically reducing your inventory is another leap of faith that will generate huge resistance: you risk customer stock-outs, and vendor problems, not to mention the removal of a safety stock of material “just in case” anything goes wrong. But clinging to excess inventory will also keep you from: freeing up a lot of floor space (where you used to store this inventory), creating a safer work place, improving your quality, lowering your costs and freeing up a significant amount of cash that you can reinvest back in the business in new products or acquisitions to grow your market share and increase your enterprise value.
Sometimes everything works just great. More often, it doesn’t. Keep leaping. Figure out what went wrong, fix it and keep moving forward. Many of the people on your team will want to stop and go back to the way you have always done it. Your job is to not let this happen. Never go backwards.
A key role for the lean leader is to push through problems as they pop up. Every business has numerous unexpected problems that seem to show up at the worst possible time. The reaction of most companies is to go backwards. A traditional batch company will respond to customer service problems, for example, by building more inventory. The lean leader on the other hand wants to lower inventory. He will push hard to uncover the root causes for the customer service problems and put fixes in place as soon as possible. Only the leader can take this approach. It is a leap of faith that you can solve the problems quickly enough so you don’t have to take a step backwards and ‘build more inventory.’ You never want to do that. It is admitting defeat, and a slippery slope in the wrong direction.
You also have to overcome the ‘lore’ that exists in almost any company or industry. By ‘lore’ I mean the beliefs that develop over time about the way something must be done and are then taken as gospel. I was once on the board of a jewelry company and showed them how to go from an eight-week lead-time for making a ring to just two days. The lore in the jewelry industry was that it takes eight weeks to make a ring. This type of lore would be perpetuated whenever anyone hired a new VP of Operations because they would look for someone with ‘jewelry industry experience.' Unfortunately, industry experience almost always comes with a fixed set of useless ideas about the way things have to be done. Every company or industry that I’ve encountered has its own ‘gospel.’ The thing is that you can’t make much progress toward becoming a lean enterprise unless you challenge these head on and get beyond them.
Of course, taking leaps of faith and overcoming industry lore requires that the leaders create an environment where it is okay to fail. Learning from your mistakes is how you get better. I was always much more worried when I hadn’t heard about a lot of small failures for a while. It made me think that maybe people were just saving up for the really big mistake that could threaten the company’s existence.