The state has been classified into groups A, B, C, D, and D+ according to industrial development.
Group A comprises the developed areas, namely the Mumbai Metropolitan Region (MMR) and Pune Metropolitan Region (PMR).
Group B comprises the areas where some development has taken place.
Group C comprises the areas which are less developed than those in Group B.
Group D comprises the lesser-developed areas of the state not covered under Group A, Group B, or Group C.
Group D+ comprises the least developed areas not covered under Group A, Group B, Group C, or Group D.