Lesson 8.7: Production Planning & Control (Inventory, Scheduling, Forecasting)

Production planning and control (PPC) is essential for efficient manufacturing operations. GATE and PSU exams often test inventory management, scheduling techniques, and forecasting methods.

🔹 1. Introduction

• Definition: PPC ensures effective use of resources, timely production, and meeting customer demands.

• Applications: Manufacturing units, process industries, assembly lines

• Key Concepts: Inventory control, scheduling, forecasting, workflow optimization

🔹 2. Production Planning

• Objective: Meet production targets with optimal resources

• Components:

  1. Routing: Path of production operations

  2. Scheduling: Timing of operations

  3. Loading: Allocation of resources

• Types of Planning:

  • Long-term: Capacity planning

  • Medium-term: Workforce and material planning

  • Short-term: Daily/weekly production schedules

🔹 3. Inventory Management

• Definition: Maintaining optimal stock levels to avoid overstock or stockouts

• Techniques:

  1. EOQ (Economic Order Quantity): Optimal order quantity minimizing total cost

  2. Reorder Point: Stock level triggering new order

  3. ABC Analysis: Classifying inventory by value and importance

• Applications: Raw materials, work-in-progress, finished goods

🔹 4. Scheduling Techniques

• Definition: Determining sequence and timing of jobs

• Methods:

  1. Gantt Chart: Visual schedule of operations

  2. Critical Path Method (CPM): Identify critical activities and project duration

  3. PERT (Program Evaluation & Review Technique): Probabilistic time estimates for project completion

• Objective: Minimize production time and maximize resource utilization

🔹 5. Forecasting Methods

• Definition: Predicting future demand to plan production and inventory

• Techniques:

  1. Qualitative: Expert opinion, Delphi method

  2. Quantitative: Moving average, Exponential smoothing, Trend analysis

• Applications: Material procurement, workforce planning, capacity allocation

🔹 6. Solved Examples (PYQ Style)

1. Calculate EOQ for a given inventory scenario

2. Determine reorder point using lead time and demand

3. Draw Gantt chart for a small job shop

4. Compute project duration using CPM/PERT

5. Forecast demand using moving average method

🔹 7. Practice Exercises

1. Solve EOQ and reorder point problems

2. Prepare Gantt chart for 5 operations

3. Identify critical path in a given project network

4. Forecast demand for 6 months using quantitative methods

5. Compare qualitative and quantitative forecasting techniques

🔹 8. Summary

• PPC: Ensures efficient production and resource utilization

• Inventory: EOQ, reorder point, ABC analysis

• Scheduling: Gantt chart, CPM, PERT

• Forecasting: Predict demand for planning

• Exam Tip: Focus on calculations, charting, and process selection