Theory of Constraints Handbook - James Cox Iii [782]
9Here we see that the groups, departments, and organizations receive TDD assessments based upon their delivery reliability. We also see that the product or project can report TDD as well. That is, the TDD assessed to a unit is also recorded with the product or project. This is not a double accounting, but a record of what group or department had unreliable delivery and also what product caused it. Having the TDD measured in this way helps management assess which organizations need help and which products/projects need improvement as well as which groups need help.
10While recovering buffer is important in process flows, it is neither rewarded nor punished. Rewarding or punishing buffer penetration or buffer recovery creates the wrong behavior; task estimates become inflated and aggressive plans are lost.
11Shippers Supply Company has used TDD for over three years. They only had to add one data element to their existing database in order to calculate the TDD. The daily TDD report is enormously effective in reducing what was an unmanageable stock level. They use the TDD report to expedite late work. They use a Pareto analysis to focus their improvement efforts. Customer service is very happy; now, customers rarely complain. The TDD numbers alert management in advance so they can take actions to fix problems before they affect delivery (Johnson, 2009).
12Figure 33-16 was first drawn by John Thompson (2009).
13www.tocico.org
1The S&T tree is one of a number of tools of the TOC Thinking Processes, which can be read about in Chapters 24 and 25 of this book. The S&T tree includes both sufficiency-based logic and necessity-based logic, which are described in those chapters and in more detail later in this chapter. The S&T tree should be written after the CRT and FRT have already been developed.
2In TOC costs are classified as totally variable costs, Operating Expense, and Investment.
3The full explanation and logic underlying finding this win-win solution is provided in Goldratt (2008a).
4The trees are available in the member section of the TOC International Certification Organization (TOCICO) Website at www.tocico.org and as part of a useful software program named Harmony for creating S&T trees at www.goldrattresearchlabs.com. Note that the most up-to-date versions of the S&T trees are automatically included in Harmony. The full Retailer S&T tree is not presented here due to space limitations. The missing steps of the full S&T tree can be downloaded at the above sites and are read in a similar manner as presented in our discussion here.
5This win-win solution is explained in The Choice (Goldratt, 2008a) in Chapters 2, 8, and 10.
6There are two buy-in processes in TOC, which are referred to as the plus and minus-minus processes.
7These solution elements were presented in The Goldratt Webcast Program on Project Management (Goldratt, 2008b).
8Note that the combination of the Retailer and CG S&T trees provides the win-win solution for both retailers and suppliers that is explained in The Choice (Goldratt, 2008a).
9It is recommended that anyone who is interested in this S&T tree review the program that Dr. Goldratt facilitated, which provides a full explanation of this S&T tree. It is available on DVD, titled “The Goldratt Webcast Program on Project Management,” at www.toc-goldratt.com.
10My suggestion for learning more about the literature on strategy is to review Thompson, Strickand III, and Gamble (2008).
11Suggestions for how to implement this approach are described in the TOC Insights into Distribution and Supply Chain, which is available at www.toc-goldratt.com.
12See the TOC Insights into Operations, which can be purchased at www.toc-goldratt.com, for a good explanation about why local efficiencies are not a good measure of performance.
13He pointed out that two additional usages of S&T trees are for project management (for choosing the project and determining its content) and as an organizer of knowledge.
1A discussion of complexity is presented in