UPSC MainsMANAGEMENT-PAPER-II201110 Marks
Q2.

Formulate the following problem as Linear Programming Problem : How much of products A and B should be produced to maximise the weekly total profit of the company?

How to Approach

This question requires formulating a real-world business problem – maximizing profit – into a mathematical model suitable for solving using Linear Programming (LP). The approach involves identifying decision variables, the objective function, and constraints. We need to define variables representing the production quantities of products A and B, express the total profit as a function of these variables (objective function), and then identify any limitations on production (constraints). The answer should clearly define each component of the LP problem.

Model Answer

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Introduction

Linear Programming (LP) is a mathematical technique used to optimize an objective function, subject to a set of constraints. It’s widely applied in business and economics for resource allocation, production planning, and various other decision-making processes. The core idea is to find the best possible solution (maximum or minimum) within a defined set of limitations. This question asks us to translate a common business scenario – maximizing profit – into the formal language of LP, setting the stage for a quantitative solution. Formulating the problem correctly is crucial, as an inaccurate model will lead to suboptimal decisions.

Formulating the Linear Programming Problem

Let's define the problem step-by-step:

1. Decision Variables

These are the variables that we have control over and whose values we need to determine. In this case:

  • Let x represent the number of units of product A to be produced weekly.
  • Let y represent the number of units of product B to be produced weekly.

2. Objective Function

This is the function we want to maximize (or minimize). Here, we want to maximize the weekly total profit. Let's assume:

  • The profit per unit of product A is PA.
  • The profit per unit of product B is PB.

Therefore, the objective function is:

Maximize Z = PAx + PBy

Where Z represents the total weekly profit.

3. Constraints

These are the limitations on our production. Constraints can arise from various factors, such as resource availability, demand, or production capacity. Let's consider some common constraints:

  • Resource Constraint 1: Suppose the production of product A requires RA1 units of resource 1 (e.g., labor hours) and product B requires RB1 units of the same resource. If the total available amount of resource 1 is A1, the constraint is: RA1x + RB1y ≤ A1
  • Resource Constraint 2: Similarly, if resource 2 is limited to A2, and products A and B require RA2 and RB2 units respectively, the constraint is: RA2x + RB2y ≤ A2
  • Demand Constraint: If the maximum demand for product A is DA and for product B is DB, the constraints are: x ≤ DA and y ≤ DB
  • Non-Negativity Constraint: Production quantities cannot be negative: x ≥ 0 and y ≥ 0

4. Complete Linear Programming Formulation

Putting it all together, the complete LP problem is:

Maximize Z = PAx + PBy

Subject to:

  • RA1x + RB1y ≤ A1 (Resource 1 constraint)
  • RA2x + RB2y ≤ A2 (Resource 2 constraint)
  • x ≤ DA (Demand for Product A)
  • y ≤ DB (Demand for Product B)
  • x ≥ 0 (Non-negativity)
  • y ≥ 0 (Non-negativity)

To solve this problem, we would need specific values for PA, PB, RA1, RB1, A1, A2, DA, and DB. The solution (values of x and y) would then be found using techniques like the Simplex method or graphical analysis.

Conclusion

In conclusion, we have successfully formulated the problem of maximizing weekly profit for a company producing two products, A and B, as a Linear Programming problem. This involves defining decision variables (production quantities), an objective function (total profit), and a set of constraints (resource limitations, demand, and non-negativity). The resulting LP model can then be solved using appropriate techniques to determine the optimal production levels for each product, leading to maximized profitability. The accuracy of the solution depends heavily on the correct identification and quantification of all relevant constraints.

Answer Length

This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.

Additional Resources

Key Definitions

Linear Programming
A mathematical method for achieving the best outcome (such as maximum profit or lowest cost) in a mathematical model whose requirements are represented by linear relationships.
Objective Function
A mathematical expression that represents the goal of a linear programming problem, either to maximize or minimize a certain quantity.

Key Statistics

The global linear programming market was valued at USD 11.4 billion in 2023 and is expected to grow at a CAGR of 13.5% from 2024 to 2030.

Source: Grand View Research, 2024 (Knowledge Cutoff: Jan 2024)

Approximately 70% of Fortune 500 companies utilize operations research techniques, including linear programming, for decision-making.

Source: INFORMS (Institute for Operations Research and the Management Sciences)

Examples

Airline Crew Scheduling

Airlines use LP to determine the optimal assignment of flight crews to minimize costs while meeting regulatory requirements and crew availability constraints.

Frequently Asked Questions

What if the objective function is not linear?

If the objective function or constraints are non-linear, the problem becomes a Non-Linear Programming (NLP) problem, which requires different solution techniques.