In the book “Systematic Maintenance Organization” from V.Z. Priel (1974), I found an interesting Multi-variable chart for the assessment of maintenance performance. This chart provides an opportunity for qualitative assessment, inasmuch as the squares can be entered to the appropriate spot representing the condition of the variable. Although the answer does not purpose to be ‘scientifically’ derived, it has advantage in expediency. So if certain conditions are satisfied the final assessment will be favorable, but one unfavorable answer may spoil the overall picture. This chart shows visually what cannot be grasp with figures presented in spreadsheets. The interdependencies becomes obvious.