Concept:
Industrial consumers often have inductive loads which draw reactive power. This reduces power factor.
Step 1: KW demand considers only active power.
Step 2: KVA demand considers both active and reactive power.
Step 3: If the reactive power load is high, the KVA demand increases.
Step 4: Therefore, KVA maximum demand tariff encourages consumers to improve power factor.
Hence, the most suitable tariff is:
\[
\boxed{\text{KVA maximum demand tariff}}
\]