Maslow's hierarchy of needs:

http://en.wikipedia.org/wiki/Maslow's_hierarchy_of_needs

Wow! Thanks for this nostagia JJ! Brought back memories (good/bad, not sure! lol) of a Business Admin HNC course from a million years ago....

I still think it's a useful model - unless A is met, then B isn't going to make much difference...and C is far off the scale - at THAT point but each level is to be aimed for (at least that's kind of how it was explained to us way back in the dark ages!!)