A ‘plan’ is a group of decisions and guidelines, most of them to be executed sometime in the future, in order to achieve a desired objective. Describing the objective, the outcome of the plan, including the criteria for determining the quality of the outcome, is the first mission of any planning.
For instance, a project plan according to CCPM is a typical group of decisions, specifying what to do, who should do, and at what sequence. The objective is to achieve the specific project output at, or before, a certain date. Meeting the specifications, the budget and being on-time constitute the criteria for most projects. All the other elements in any planning should be derived from the objective.
When the desired objective is not achieved as planned we cannot easily determine whether it is due to a flawed plan, mistakes done in the execution or rare bad luck.
Or can we?
When consistently the objectives are not achieved then most likely the core problem is a flaw in the planning. After all, limitations in the capabilities or capacities of the resources should be dealt with in the planning.
Achieving an objective faces two problems:
- Complexity, too many variables with partial-dependencies between them.
- Uncertainty – the fluctuations of the key variables on top of the dependencies.
One of the most important insights I learned from Eli Goldratt:
The combination of complexity and uncertainty makes the situation SIMPLER!
Because uncertainty outlines the boundaries of what we don’t know, Goldratt called it “the noise in the system.” We should ignore variables that their impact relative to the noise is low. Our expectations from any proposed change should be way above the noise/uncertainty in the system. Other changes do not matter at all.
A necessary element in any plan:
The timing of making any decision is an important factor. On one hand a decision taken too early exposes itself to considerable uncertainty. On the other hand we do not want to delay the decision until it is too late. Any detailed instruction in the planning has to have a good answer to:
Isn’t it too early to finalize that instruction?
What about letting the people at the execution phase decide when the time is appropriate?
For instance, should we include every nice-to-have feature in the planning of a new product? At the time of the planning we don’t know the exact pressure on capacity and the value of this feature in the face of the competition. Wouldn’t it be better to delay that decision to a later point in time where the actual work on that feature should start to ensure meeting the due-date?
What comes out is that the plan has to be truly lean, including only the most critical elements that any deviation from might damage or delay achieving the objective.
Another necessary element in any plan:
Protecting the objective from whatever could threaten it. TOC uses buffers to protect due-dates and availability. We should also consider buffers for capabilities, capacity, budget and key risks of the technology used.
The impact of the two elements on the planning:
- Any plan has to include ONLY the elements that leaving them to a later stage might cause serious damage. The plan could include generic guidelines for later decisions and checklists to ensure they won’t be skipped by mistake.
- The planning includes visible and well defined buffers protecting the sensitive and vulnerable elements in the planning.
The role of the execution is to achieve the planning objective(s). The more decisions are left to the execution the more flexibility to face uncertainty. But, synchronization issues, important requirements and other wide-effect decisions are better handled in the planning.
In the last twenty years we saw the formidable failures of several key planning methodologies. Many advanced-planning-and-scheduling (APS) software packages, like i2 and the APO by SAP, almost vanished. The common undesired-effect of those methodologies is vulnerability to common and expected uncertainty. In many ways the common project management planning methods have been exposed to frequent missing due-dates and content. Planning of budgets, with a lot of detailed entries, is a similar ridiculous kind of planning widely exposed to uncertainty.
The failures of sophisticated planning methodologies initiated movements that bypass planning and concentrate only on execution. However, abandoning planning generates several negative branches, like failing to reach any truly desirable objective, and not supplying top management with critical information: what time and value commitments we are able to promise our customers?
The TOC way is to plan holistically the objectives and put them into the timeline, protecting whatever is truly important by the use of buffers. In the end of the day, the use of visible buffers is a paradigm shift that we, the TOC community, do not fully grasp the full meaning. For instance, where are the buffers in the S&T?