This post is a kind of post scriptum to “Improving 50% is easy, improving 5% is difficult” in which I described 3 stages of improvement and ended stuck with continuous improvement as the Return On Investment (ROI) in C stage was not worth going on.
Now assume it is not possible to radically change the process (kaikaku), because for instance it has been approved by some authority (customer, regulatory…), being on the verge of C stage does not necessarily mean this is permanent.
If the limitation to improve further are skills or experience, the situation may change over time as trainings are delivered, experience is accumulated or necessary skills hired.
If the limitation is the cost of some solution, like changing material or buying some equipment, this too may change over time and become affordable / change the ROI, thus providing opportunities to improve further without changing everything.
What wasn’t possible or reasonable at some point may become possible and meaningful.
It is therefore important to revisit the assumptions and conclusions of the improvement workshops /projects periodically and check if some conditions have changed in a favorable manner.
This is also why, after a Value Stream Mapping and/or some diagnostic was done, designing the future state should first attempt to design a perfect process. This frees the designers from actual constraints and limitations and can lead to interesting solutions.
In a second step, the constraints and limitations are brought back in and the ideal solution trimmed down to what is possible given the limitations, e.g. state of industry vs. state of art, technological or economical limitations, limited know-how, etc.
But all brainstorming ideas and drafts of a perfect process/ideal state should be kept in a kind of think tank and periodically checked. It may happen that one of the ideas, impossible at a given moment can now be envisioned, thanks to some evolution.