🏭Intro to Industrial Engineering Unit 5 – Production Planning & Scheduling

Key Concepts and Terminology

• Production planning involves coordinating and optimizing resources, materials, and processes to meet customer demand efficiently
• Scheduling determines the sequence and timing of production activities to maximize efficiency and meet deadlines
• Capacity planning ensures sufficient resources (equipment, labor, materials) are available to meet production targets
• Inventory management balances holding costs with the need to have sufficient materials and finished goods on hand
• Lead time represents the total time required to complete a product from start to finish, including processing, waiting, and transport times
• Bill of Materials (BOM) itemizes the raw materials, sub-assemblies, and components needed to manufacture a product
• Material Requirements Planning (MRP) is a system for planning and scheduling production based on sales forecasts, BOMs, and inventory levels
• Gantt charts visually represent the schedule and progress of production activities over time

Importance of Production Planning

• Effective production planning optimizes resource utilization (machinery, labor, materials), reducing waste and increasing efficiency
• Helps ensure customer orders are fulfilled on time, improving customer satisfaction and loyalty
• Allows for better coordination and communication between different departments (sales, purchasing, production)
• Enables proactive identification and resolution of potential bottlenecks or capacity constraints
• Facilitates accurate forecasting of material and labor requirements, reducing stockouts or overstocking
• Improves overall productivity and profitability by minimizing downtime, overtime, and expediting costs
• Provides a framework for continuous improvement by identifying opportunities to streamline processes and reduce lead times

Production Planning Process

• Starts with demand forecasting to predict future customer orders based on historical data, market trends, and sales projections
• Develops a master production schedule (MPS) that outlines the quantities and timing of finished products to be produced
• Creates a detailed material requirements plan (MRP) to ensure necessary raw materials and components are available when needed
  • MRP explodes the BOM to determine the quantities and timing of each item required
  • Factors in lead times, safety stock levels, and supplier capabilities
• Assesses available capacity (equipment, labor) and identifies any constraints or bottlenecks
• Generates a detailed production schedule that sequences and assigns specific orders to work centers
• Monitors progress against the plan, adjusting as needed based on actual demand, quality issues, or other disruptions
• Analyzes performance metrics (on-time delivery, inventory turns, capacity utilization) to identify areas for improvement

Scheduling Techniques and Methods

• Forward scheduling starts with the order release date and calculates the earliest finish date based on lead times and available capacity
• Backward scheduling starts with the due date and works backward to determine the latest possible start date
• Finite capacity scheduling considers actual resource availability and constraints when generating the schedule
  • Helps identify potential bottlenecks and over-utilization of resources
  • May require adjusting due dates or adding overtime/additional shifts to meet demand
• Infinite capacity scheduling assumes unlimited resource availability, providing a best-case scenario for meeting demand
• Priority rules determine the sequence of orders based on criteria such as due date, order value, or customer importance
• Advanced planning and scheduling (APS) software uses algorithms and heuristics to optimize complex, multi-constraint scheduling problems

Capacity Planning and Resource Allocation

• Determines the maximum output that can be produced given available resources (equipment, labor, materials)
• Rough-cut capacity planning (RCCP) estimates capacity requirements based on the master production schedule and standard lead times
• Capacity Requirements Planning (CRP) generates a detailed load profile for each work center based on the production schedule
  • Identifies periods of over- or under-utilization
  • Helps make decisions about adding overtime, subcontracting, or investing in additional equipment
• Resource allocation assigns specific orders and tasks to individual machines and operators
• Capacity planning strategies include:
  • Level capacity maintains a consistent output rate, building inventory during slow periods to meet peak demand
  • Chase capacity adjusts output to match demand fluctuations, minimizing inventory but potentially requiring overtime or temporary workers

Inventory Management in Production

• Ensures sufficient raw materials, work-in-progress (WIP), and finished goods are available to meet production and customer requirements
• Economic Order Quantity (EOQ) model determines the optimal order size that minimizes total holding and ordering costs
• Reorder point (ROP) triggers a new order when inventory levels reach a predetermined threshold, considering lead time and safety stock
• Just-in-Time (JIT) inventory management aims to minimize inventory by synchronizing supplier deliveries with production needs
  • Requires close coordination with suppliers and reliable transportation
  • Can reduce holding costs and improve cash flow but increases risk of stockouts
• ABC analysis categorizes inventory items based on their value and importance, allowing for differentiated management strategies
• Cycle counting involves regularly verifying inventory accuracy for a subset of items rather than conducting a full physical inventory

Technology and Software Tools

• Enterprise Resource Planning (ERP) systems integrate data from multiple functions (sales, purchasing, production, finance) to support decision-making
• Manufacturing Execution Systems (MES) track and document the transformation of raw materials into finished products in real-time
  • Provides visibility into production status, quality, and performance
  • Enables real-time adjustments to the schedule based on actual conditions
• Advanced Planning and Scheduling (APS) software uses algorithms and heuristics to generate optimal production schedules considering multiple constraints
• Warehouse Management Systems (WMS) support efficient inventory tracking, storage, and retrieval
• Barcoding and Radio-Frequency Identification (RFID) technologies enable accurate, real-time tracking of inventory and WIP
• Internet of Things (IoT) sensors and devices can monitor equipment performance, quality, and material flow in real-time

Real-World Applications and Case Studies

• Toyota Production System (TPS) pioneered lean manufacturing principles, including just-in-time inventory, continuous improvement, and visual management
  • Enabled Toyota to minimize waste, improve quality, and respond quickly to changing customer demands
  • Became a model for manufacturing excellence across industries
• Dell's make-to-order production system allows customers to configure products to their specifications
  • Requires tight integration between sales, purchasing, and production to minimize lead times and inventory
  • Relies on advanced planning and scheduling software to optimize production sequences and resource allocation
• Zara's fast fashion model relies on rapid design, production, and distribution to capture the latest trends
  • Vertically integrated supply chain enables quick response to market demands
  • Frequent small batch production minimizes inventory risk and allows for greater product variety
• GE Aviation uses advanced analytics and digital twins to optimize production planning and scheduling for aircraft engines
  • Simulates various scenarios to identify the best production sequence and resource allocation
  • Enables proactive identification and resolution of potential bottlenecks or quality issues