There are three tests to apply to every situation. Sometimes these tests require considerable research and thought and require you to spend time reasoning through your own biases to gain objectivity. 

If the situation cannot produce IFR zero in the real-world (after appropriate analysis do not simply assume this is not possible), the relevant next set of questions are twofold. To get there we will need to go through some definitions first.

• Best Possible Solution (BPS) - The best possible combination of a systems configuration given the system exists; or, the best next step in the direction of the IFR.

If it is not possible to realize the IFR at this stage, analysis should be conducted concerning the BPS with a focus on the systems ideality and output value. 

The first test is always “What would it take to remove the need for this output in this case?”

In its purest form, the IFR for any system output is the constant zero, meaning the supersystem has successfully evolved to provide the value of the team output without any cost, harms, or problems, making the system output no longer needed as a component of the supersystem.

IFR = 0

• Ideal Final Result (IFR) - The perfect combination of a systems configuration that all value is recognized without any cost, problems, or harms.

Now, this is not suggesting that the perfect solution to every problem is to eliminate the team of people that produce output. That is a consistent but erroneous impulsive reaction when introduced to the concept of the IFR being zero. 

Remember, TSoT is a continuous improvement framework, when an IFR reaches zero it means the system has evolved to being resource positive and that teams can be assigned new work to build on existing organization capability to add new value or create new efficiencies.

This can be a difficult concept to accept as it stretches our embracing philosophically lean and efficient to its farthest conception; understanding the need for this though is key to understanding TSoT. As systems form and evolve the ideal state of the system is improved the closer it approaches zero, meaning the closer it can provide ideal benefits at perfect efficiency with no costs, problems, or harms. 

There are many examples of roles and systems coming and going. An example could be the mail room at a small bank, where for many decades value was provided by sending out monthly bank statements; today many small banks only provide those statements online, delivering the value of a bank statement to their customers without the cost, problems, and harms of sending out paper statements. We will cover several examples later to emphasis this concept.

A systems BPS is the process of bringing its ideality and value into balance 

BPS ↔ I + V

A systems ideality is when its efficiency exceeds its problems and any harms, so an ideal system delivers the highest efficiency with no problems or harms

I  ↔ E > PH

An efficient system delivers actual output equal to or in excess of is its required output, so the most efficient system will deliver actual output at or higher than its required output

E ↔ A > R

Apply the fraction rule to simplify the formula for system Ideality, a systems ideality is when its actual output equals or exceeds its required output and any harms or problems of reaching its required output

I  ↔ A > RPH

A system is valuable when its benefits exceed the cost of the benefits, so the highest value system delivers the highest benefit with the lowest costs

V ↔ B > C

Substituting in all the definitions, a systems best result is when its efficiency exceeds required output and any problems or harms of its output plus its benefits compared to its costs 

BPS ↔ ( ( A > RPH ) + ( B > C) )

The second and third solution tests focus on identifying the delta necessary to bring ideality and value into balance.