所谓的efficiency paradox，是关注resource efficiency带来的问题。作者提到三类问题：
The first source of inefficiency: long throughput times... Long throughput time generates secondary needs...
The second source of inefficiency: many flow units... Handling many flow units generates secondary needs
The third source of inefficiency: many restarts per flow unit... Many restarts generate secondary needs
原因呢？用作者的话来说：
But what is the root cause of secondary needs? Essentially, an over-focus on resource efficiency creates low flow efficiency.
This creates “efficient islands” in which fulfillment of customer needs is split up into several, smaller steps that are performed by various individuals or parts of an organization.
No one island has a full overview of the entire process; each island sees only its own part.
总之，带来的这些二次需求，意味着flow的减慢 —— 而这意味着什么呢？很可能是不创造顾客价值，或者创造价值、但是顾客不付费的二次需求（因为被其他负面效应给对冲掉了）：
Secondary needs are harmful for organizations since they generate what we call superfluous work, or work devoted to taking care of secondary needs. Superfluous work is a very sophisticated form of waste, since we often fail to realize that it is waste. We think we are adding value, but we are not. Nevertheless, we still have to take care of secondary needs.
丰田称之为七种浪费，都是由于流动减慢带来的资源闲置、闲置带来的管理需求、浪费甚至偷盗等风险 —— 为了应对此类风险，丰田提出的理想目标叫做：one-piece flow。
而TOC提出的是，DBR、关键链等，也是关注整个流动的效率，而不是单点的效率。
是的，如果能每次只流动一件、或者迫于无奈让瓶颈的流动最快，一定是能提升流动效率，也倒逼资源方提升资源的灵活性 —— 或者高大上的说法叫做“敏捷”。
