Two environmental themes are associated with materials and energy (the first
three core objectives). First, no more energy and materials should be used than absolutely
necessary (conservation issue). Second, means should be sought to eliminate
the usage of materials and energy that damage the environment (hazardous substance
issue). Performance measures should reflect these two themes. Thus, possible measures
would be total and per-unit quantities of the different types of materials and
energy (e.g., pounds of toxic chemicals used), productivity measures (output/materials,
output/energy), and hazardous materials (energy) costs expressed as a percentage
of total materials cost.