Theory of Constraints Handbook - James Cox Iii [664]
Key Concepts Regarding Creation of S&T Trees
We have been using S&T trees to guide TOC VV implementations for years now. VV projects are holistic TOC implementations. These VV projects consist of multiple, synchronized TOC applications (subsystem implementations), such as operations, distribution, project management, marketing, and sales. VV projects are consulting projects in which the target net profit in four years or less will be significantly higher than the best possible profit that top management of the company believes is achievable. S&T trees can be used to achieve any strategy of any system (such as any type of organization or for a person). Once an S&T tree has been developed, it is necessary to first verify that the strategy, which is one of a number of strategies we have, applies to the system (person or organization) for which the S&T tree is written. The assumptions really are facts of life. We need to validate that they are facts of life for a particular system. If they are not facts, then the corresponding strategy or tactic does not apply to the given system.
The S&T tree provides all the strategies and tactics needed to achieve the strategy in the step in Level 1. The S&T tree provides answers to the three questions in TOC regarding how to manage effectively:
1. What to Change?
2. What to Change to?
3. How to Cause the Change?
The S&T trees that were developed to guide VV implementations provided the first significant application of TOC to answer the third question above. The development of these S&T trees clarified the steps for successfully implementing TOC. The guidance provided in Level 5 of the VV S&T trees is very useful for implementing TOC in an application/subsystem (such as a function). Level 5 provides a simplified approach to implementation that ensures that only the injections (solution elements) required are implemented and provides information regarding the sequence of implementing those injections.
The project network/plan for implementing the VV project consists only of the tactics in the lowest level of the S&T tree. In other words, a network showing all the dependencies (both task and resource) will be created based on all the tactics in the S&T tree at the lowest level. Specifically, if a step does not include a Level 5 while others do, then we will have tactics in the project plan from both Levels 4 and 5. This project plan in VV implementations is created using the Critical Chain network (which includes all dependencies and appropriate buffers) and is managed using critical chain software (from Realization Technologies).
The VV S&T trees also include strategies and tactics for ensuring that significant negative branch reservations (NBRs) are trimmed, thus ensuring that any significant, potential negative consequences of implementing the solution are prevented. In addition, these S&T trees include strategies and tactics for ensuring that significant obstacles that may block or delay implementation are overcome.
The VV S&T trees are written to follow the plus buy-in process of TOC.6 The steps of the plus buy-in process are:
1. Agree on the very ambitious objective we desire to reach—a pot of gold.
2. Agree that reaching the pot of gold at the top of the cliff is much more difficult than we originally thought.
3. Agree that there is a direction for the solution, an anchor on the cliff against which a ladder can be leaned.
4. Agree on the solution details.
5. Overcome unverbalized fears, such as the potential