An Improvement-by-Design challenge is very like a Sudoku puzzle. The rules are deceptively simple but the solving the puzzle is not so simple.

For those who have never tried a Sudoku puzzle the objective is to fill in all the empty boxes with a number between 1 and 9. The constraint is that each row, column and 3×3 box (outlined in bold) must include all the numbers between 1 and 9 i.e. no duplicates.

What you will find when you try is that, at each point in the puzzle solving process there are more than one choice for most empty cells.

The trick is to find the empty cells that have only one option and fill those in. That changes the puzzle and makes it ‘easier’.

And when you keep following this strategy, and so long as you do not make any mistakes, then you will solve the puzzle. It just takes concentration, attention to detail, and discipline.

In the example above, the top-right cell in the left-box on the middle-row can only hold a 6; and the top-middle cell in the middle-box on the bottom-row must be a 3.

So we can see already there are three ways ‘into’ the solution – put the 6 in and see where that takes us; put the 3 in and see where that takes us; or put both in and see where that takes us.

The final solution will be the same – so there are multiple paths from where we are to our objective. Some may involve more mental work than others but all will involve completing the same number of empty cells.

What is also clear is that the sequence order that we complete the empty cells is not arbitrary. Usually the boxes and rows with the fewest empty cells get competed earlier and those with the most empty cells at the start get completed later.

And even if the final configuration is the same, if we start with a different set of missing cells the solution path will be different. It may be very easy, very hard or even impossible without some ‘guessing’ and hoping for the best.

Exactly the same is true of improvement-by-design challenges.

The rules of flow science are rather simple; but when we have a system of parallel streams (the rows) interacting with parallel stages (the columns); and when we have safety, delivery, and economy constraints to comply with at every part of the system … then finding and ‘improvement plan’ that will deliver our objective is a tough challenge.

But **it is possible** with concentration, attention-to-detail and discipline; and that requires some flow science training and some improvement science practice.

OK – I am off for lunch and then maybe indulge in a Sudoku puzzle or two – just for fun – and then maybe design an improvement plan to two – just for fun!