The Lean Startup - Eric Ries [74]
In Chapter 12, we’ll come full circle. As startups grow into established companies, they face the same pressures that make it necessary for today’s enterprises to find new ways to invest in disruptive innovation. In fact, we’ll see that an advantage of a successful startup’s rapid growth is that the company can keep its entrepreneurial DNA even as it matures. Today’s companies must learn to master a management portfolio of sustainable and disruptive innovation. It is an obsolete view that sees startups as going through discrete phases that leave earlier kinds of work—such as innovation—behind. Rather, modern companies must excel at doing multiple kinds of work in parallel. To do so, we’ll explore techniques for incubating innovation teams within the context of an established company.
I have included an epilogue called “Waste Not” in which I consider some of the broader implications of the success of the Lean Startup movement, place it in historical context (including cautionary lessons from past movements), and make suggestions for its future direction.
9
BATCH
In the book Lean Thinking, James Womack and Daniel Jones recount a story of stuffing newsletters into envelopes with the assistance of one of the author’s two young children. Every envelope had to be addressed, stamped, filled with a letter, and sealed. The daughters, age six and nine, knew how they should go about completing the project: “Daddy, first you should fold all of the newsletters. Then you should attach the seal. Then you should put on the stamps.” Their father wanted to do it the counterintuitive way: complete each envelope one at a time. They—like most of us—thought that was backward, explaining to him “that wouldn’t be efficient!” He and his daughters each took half the envelopes and competed to see who would finish first.
The father won the race, and not just because he is an adult. It happened because the one envelope at a time approach is a faster way of getting the job done even though it seems inefficient. This has been confirmed in many studies, including one that was recorded on video.1
The one envelope at a time approach is called “single-piece flow” in lean manufacturing. It works because of the surprising power of small batches. When we do work that proceeds in stages, the “batch size” refers to how much work moves from one stage to the next at a time. For example, if we were stuffing one hundred envelopes, the intuitive way to do it—folding one hundred letters at a time—would have a batch size of one hundred. Single-piece flow is so named because it has a batch size of one.
Why does stuffing one envelope at a time get the job done faster even though it seems like it would be slower? Because our intuition doesn’t take into account the extra time required to sort, stack, and move around the large piles of half-complete envelopes when it’s done the other way.2 It seems more efficient to repeat the same task over and over, in part because we expect that we will get better at this simple task the more we do it. Unfortunately, in process-oriented work like this, individual performance is not nearly as important as the overall performance of the system.
Even if the amount of time that each process took was exactly the same, the small batch production approach still would be superior, and for even more counterintuitive reasons. For example, imagine that the letters didn’t fit in the envelopes. With the large-batch approach, we wouldn’t find that out until nearly the end. With small batches, we’d know almost immediately. What if the envelopes are defective and won’t seal? In the large-batch approach, we’d have to unstuff all the envelopes, get new ones, and restuff them. In the small-batch approach, we’d find this out immediately and have no rework required.
All these issues are visible in a process as simple as stuffing envelopes, but they are of real and much greater consequence in the work