Facility layout: the process of determining placement of departments, workgroups within departments, workstations, machines, and stock-holding points within a facility
This process requires the following inputs:
Specification of the objectives used to evaluate the design
Estimates of product or service demand
Space requirements for the elements
Space availability within the facility
Basic Production Layout Formats
Workcenter (job-shop or functional layout)
Similar equipment are grouped together.
Assembly line (flow-shop layout)
Work processes are arranged according to the steps by which the product is made.
Dissimilar machines are grouped to work on similar products.
Product remains at one location.
The flow (number of moves) to and from all departments
The cost of moving from one department to another
The existing or planned physical layout of the plant
The “best” locations for each department, where best means maximizing flow, which minimizes costs
Example 8.1: Interworkcenter Flow Graph with Number of Annual Movements
Assembly line: progressive assembly linked by some material handling device
Some form of pacing is present and the allowable processing time is equivalent for all workstations
Material handling devices
Workstation cycle time: a uniform time interval in which a moving conveyor passes a series of workstations
Also the time between successive units coming off the line
Assembly-line balancing: assigning all tasks to a series of workstations so that each workstation has no more than can be done in the workstation cycle time
Precedence relationship: the order in which tasks must be performed in the assembly process
Specify the sequential relationships among tasks.
Determine the required workstation cycle time.
Determine the theoretical minimum number of workstations.
Select a primary and secondary assignment rule.
Evaluate the efficiency of the balance.
Rebalance if needed.
Split the task
Share the task
Use parallel workstations
Use a more skilled worker
Flexible Line Layouts
Problem – operators trapped in “cages” prevents sharing work among them
Solution – remove barriers so operators can trade work and operators can be added or removed as needed
Flexible Line Layouts
Problem – operators “birdcaged” with no opportunity to share work or add third operator
Solution – operators can help each other and third operator can be added if needed
Flexible Line Layouts
Problem – straight line is difficult to balance
Solution – U-shaped line gives better operator access and may reduce need for operators
Mixed-Model Line Balancing
Most factories produce a number of different products.
Inventory can be reduced by building some of each product during every period (e.g., day, week, etc.).
Mixed-model line balancing is one means of scheduling this varied production.
Developing a Manufacturing Cell
Grouping parts into families that follow a common sequence of steps
Identifying dominant flow patterns of parts families as a bases for location of processes
Physically grouping machines and processes into cells
Example: Original Workcenter Layout
Example: Routing Matrix Based upon Flow of Parts
Example: Reallocating Machines to Form Cells
Manufacturing Cell Benefits
Better human relations
Improved operator expertise
Less in-process inventory and material handling
Faster production setup
Is characterized by a relatively low number of production units.
Visualize the product as the hub of a wheel with materials and equipment arranged concentrically around the production point.
A high degree of task ordering is common.
To the extent that this precedence determines production stages, a project layout might be developed by arranging materials according to their technological priority.
Retail Service Layout
Goal—maximize net profit per square foot of floor space
Background characteristics, such as noise
Spatial layout and functionality
Planning the circulation path of customers and grouping merchandise
Signs, symbols, and artifacts
Parts of the service that have social significance
Alternative Store Layouts
Marketing Research and Retail Layout
People in supermarkets tend to follow a perimeter pattern in their shopping behavior. Placing high-profit items along the walls of a store will enhance their probability of purchase.
Sale merchandise placed at the end of an aisle in supermarkets almost always sells better than the same sale items placed in the interior portion of an aisle.
Credit and other non-selling departments that require customers to wait for the completion of their services should be placed either on upper floors or in “dead” areas.
In department stores, locations nearest the store entrances and adjacent to front window displays are most valuable in terms of sales potential.
More open offices
Low divider walls
Size and orientation of desks indicates importance of people behind them
ServiceMaster (A major janitorial firm) places its
know-how room (tools , manuals) at the center