Intangibles are those things that are not clearly perceptible. Many of the benefits of Lean appear, at first glance, to fall into this category.
Upon deeper consideration, though, you will likely find that many intangibles can actually be measured. ‘Morale’ seems intangible, but can be measured by turnover, satisfaction surveys, or even the quantity of laughter in the company.
Even things like beauty (facial symmetry), anger (volume of voice, heart rate, or shade of red on the cheeks), or leadership (response time of subordinates, or number of complaints in the suggestion box) can all be measured.
The point is to not immediately dismiss performance factors as intangible. Often, they just require a bit of effort to find a creative way to measure them. And, of course, being able to measure something is critical to being able to confirm that it has been improved.