Facility Layout and Location

Why it matters

Facility layout and location are critical in industrial engineering as they directly impact the efficiency of production processes, cost management, and overall productivity. Proper layout and location decisions can lead to reduced material handling costs, improved workflow, and enhanced safety.

Key ideas

• Facility Layout: Refers to the arrangement of physical facilities such as machinery, equipment, and furniture within a factory or service facility. The goal is to optimize the workflow and minimize costs.
  • Types of Layouts:
    • Product Layout: Used for mass production; equipment is arranged according to the sequence of operations.
    • Process Layout: Suitable for job shops; similar processes are grouped together.
    • Fixed Position Layout: Used when the product is too large to move; workers and equipment come to the site.
    • Cellular Layout: Combines elements of both product and process layouts; used for batch production.
• Facility Location: Involves selecting a geographical location for a facility. Factors include proximity to suppliers and customers, transportation costs, and labor availability.
  • Location Models:
    • Factor Rating Method: A qualitative method using weighted scores for different factors.
    • Center of Gravity Method: A weighted-coordinate heuristic. It exactly minimizes weighted squared Euclidean distances in an unconstrained plane, but generally does not minimize actual road transport costs or weighted ordinary distances.
    • Load-Distance Method: Evaluates locations based on the load and distance to minimize costs.

Formulas

• Load-Distance = Σ (Load_i × Distance_i)
  • Load_i: Load or weight associated with location i (for example, tonnes per year)
  • Distance_i: Distance to location i (meters)
• Center of Gravity (X, Y) = (Σ (X_i × W_i) / Σ W_i, Σ (Y_i × W_i) / Σ W_i)
  • X_i, Y_i: Coordinates of location i (meters)
  • W_i: Weight or load at location i (consistent load units)

Worked example

Given: Three demand points with coordinates and weights: A (2, 3, 10), B (5, 7, 20), C (8, 6, 15).

1. Calculate the weighted coordinates for each location.
   • For A: (2 × 10, 3 × 10) = (20, 30)
   • For B: (5 × 20, 7 × 20) = (100, 140)
   • For C: (8 × 15, 6 × 15) = (120, 90)
2. Sum the weighted coordinates and weights.
   • Total weighted X: 20 + 100 + 120 = 240
   • Total weighted Y: 30 + 140 + 90 = 260
   • Total weight: 10 + 20 + 15 = 45
3. Calculate the center of gravity.
   • X = 240 / 45 = 5.33
   • Y = 260 / 45 = 5.78

Final Answer: The weighted-coordinate candidate is at coordinates (5.33, 5.78) meters.

Validate the candidate against road routes, capacity, land availability and other constraints before selecting a facility.

Common mistakes

• Confusing product and process layouts, leading to inefficient designs.
• Ignoring qualitative factors in location decisions, such as community impact.
• Miscalculating weighted averages in the center of gravity method.

For GATE ME

Questions often involve calculating optimal facility locations using quantitative methods like the center of gravity or load-distance. Practice problems involving different layout types and their applications in various industrial scenarios.

Quick check

1. What is the main goal of facility layout?
2. Name two quantitative methods for facility location.
3. What type of layout is best for mass production?

Answers: 1. Optimize workflow and minimize costs. 2. Center of Gravity, Load-Distance. 3. Product Layout.