a$)$ Discuss the concept and basic assumptions in limiting factor analysis.

b$).$ A company makes four products: W$,$ X$,$ Y and Z$,$ using the same direct material in the manufacture of all the products. Budgeted data for one month is as follows:

$\backslash$table$[[$Product$,$W$,$X$,$Y$,$Z$],[$Monthly sales demand $($units$)400,400,600,300,],[,$#$,$#$,$#$,$#