MECH SHALA's video: The Big M Method Artificial variable

The Big M Method or M technique or Method of Penalties. this method is used where simplex method get failed due to different nature of constraints. if all constraints are in either less than equal or greater than equal then we can use simplex method if there is the combination of less than equal or greater than equal in the same problem then we have to use artificial variable in the constraints having greater than equal or = signs. this method consists of following basic steps: step:-1 introduce slake, surplus variable in LHS side of constraints having greater than equal and less than equal sign respectively. step:- 2 add artificial variable in lhs part of constraints having either greater than equal or = sign. step:- 3 modified the objective function by using 0 coefficient of surplus as well as slake variable. for artificial variable- in maximization problem:- -M in minimization problem :- +M Note:- we use artificial variable to get initial basic feasible value only, it have no significant meaning. step:-4 solve the modified LP by the simplex method.