Your task is to raise a block from the ground up to the peak of a ramp. The level of difficulty of this activity will depend upon many factors, such as the ramp inclination, the block weight, the length of the ramp, the height of the ramp peak, the friction coefficient between the block and the ramp and that you have to make that effort alone or as a team (Figure 1).
Now, imagine that instead of a block you were trying to elevate a sphere to the same place. It would be easier to roll the sphere all the way to the top of the ramp than moving the block. By changing the shape of the object, the degree of difficulty in accomplishing your goal is significantly reduced (Figure 2). In the end, the sphere would have been rotated from the lowest level (current state) to the highest level (target, or final state) over a period of time, as a result from the effort applied to this activity (Figure 3).
If the activity of rolling the sphere to the peak of the ramp had to be planned and executed as a project life cycle, the total effort and timeline required to complete the task would have to be known. The milestones within that timeline, such as the height achieved (= level) at any given point in time or phase also have to be known in order for you to track progress and assess whether or not your plan is on track.
Most ERP projects are planned to be executed under the same principles. What has occurred is when the Project Managers begin their project they notice the sphere that is to be moved up the ramp is still in the shape of a block. To follow the plan as written is not an option.
There has to be either an additional plan to shape the block into a sphere or to change the variables in the plan to meet the new specifications. Eventually they might succeed but the transition to the sustain mode of the original plan might now not be suitable for this application and the sphere or block might begin to descend on the ramp. Simply put: the ball is dropped!