Terminologies used in Operations Research

Hey there! in this post we are going to introduce terminologies in OR, such as Objective function, Net evaluation row, key column, Key row, key number, etc.  Initially, we’ll discuss what LPPs are..

What are LPPs?

LPP (Linear Programming Problem) these problems are about minimizing or Maximizing a certain given function, with respect to some conditions provided in the problem. The main function is the ‘Objective Function’ which is to be maximized or minimized and the conditions, that is, inequalities – are’Constraints’.

Some important terminology in LPP:

Here are discussed some terminologies which plays key role in Operations Research (such as-Net evaluation row, Objective function, Key row, Key column, Objective function,etc.), so that the subject can be easy with their help.

Objective Function:

An’Objective Function’ is a linear function, which maximizes or minimizes subject to the set of linear conditions.


‘Constraint’  is A  set of linear conditions subject to which the objective function minimizes or maximizes.

Feasible Constraints:

Feasible condition is the condition of non-negativity of constraints.

Slack Variables:

Slack variables are just arbitrary variables which convert ineqality constraints into equations.

Surplus Variables:

Slack variables used along with the artificial variables, are Surplus Variables.

Artificial Variables:

In (=) type L.P.P, a non negative variable added to convert given L.P.P. into standard form, that non  negative variable is the Artificial Variable.

Net Evaluation Row:

Net evaluation row is an index row that represents net contribution of a unit of each variables if added to the product mix.

Key Column:

In the Net Evaluation Row, the column showing maximum (or say minimum) value, in maximization (or minimization) problem.(irrespective of its sign) that is the Key Column.

Key Row:

The quantity of variables is divided by the numbers that are in key column that is the ‘ratio’. The row with minimum ratio is the Key row.

Key Number:

the number is a key number if that is in the intersection of key row & key column that is the key number.

These are the basic concepts on Operations Research. Now, go through the Methods of solving problems in OR, in our next post Introduction to Operations Research. Hope this would also be as helpful as our other posts to you…