Operations Management: Layout, JIT, and Theory of Constraints

Facility Layout Strategies

• Office Layout: Focuses on the efficient transfer of information between departments and workstations.
• Shop Distribution: Aims to maximize net profit per square meter of shelf space.
• Warehouse Distribution: Seeks the optimal balance between material handling costs and storage space utilization.

Line Balancing and Task Assignment

• Task Assignment: Utilizes the rule of maximum successive tasks, prioritizing tasks with longer execution times for initial assignment, leaving shorter tasks for precise adjustments.
• Helgeson and Birnie Methodology: Tasks are selected based on the cumulative execution time of the task plus all subsequent tasks; the task with the highest total is prioritized.

Just-in-Time (JIT) Production

Objective: Increase company profit by reducing costs through the production of the exact quantity of elements required at the precise moment.

The Five Zeros

Eliminating defects, inventory, breakdowns, delays, and paperwork.

Key JIT Concepts

• Shojinka: Adapting to market demand through operational flexibility.
• U-Shaped Cells: Enables operators to access multiple machines, facilitates visual inspection, reduces setup times, and improves communication. Includes task rotation.
• Soikufu: Encouraging and implementing worker suggestions to improve operations and productivity.
• Jidoka: Autonomous defect control; statistical methods are often insufficient.
• Poka-Yoke: Mechanisms that automatically prevent errors.

Kanban Systems

A pull system using cards to manage production across work centers. Requires flow diagrams, organized warehouses, and dedicated mailboxes for items.

• Transport Kanban: Tracks item identification, container capacity, order sequence, origin, and destination.
• Production Kanban: Tracks item identification, manufacturing work center, container capacity, and components.

Theory of Constraints (TOC)

The primary goal of a company is to earn money. The performance of any chain is determined by its weakest link.

• Constraint: Capacity of resource > Workload.
• Bottleneck: Capacity < Workload. The system operates at the speed of the constraint.

TOC Principles for Operations

1. Balance the production flow, not the production capacity.
2. Non-bottleneck resource usage is determined by system constraints, not individual capacity.
3. Distinguish between usage (achieving a goal) and activation (performance without profit).
4. An hour lost at a bottleneck is an hour lost by the entire system.
5. Additional capacity in non-bottleneck resources does not increase total system capacity.

DBR (Drum, Buffer, Rope) Solution

1. Identify bottlenecks.
2. Program the bottlenecks.
3. Program work centers following the bottleneck.
4. Program work centers preceding the bottleneck.
5. Program non-bottleneck resources that process materials for assembly with bottleneck components.