FACILITY LAYOUT INOPERATIONS MANAGEMENT

BY: RAHUL TEJYAN11/PMB/O33

Facility layout

Layout decisions entail determining the placement of departments, work groups within the departments, workstations, machines, and stock-holding points within a production facility. The objective is to arrange these elements in a way that ensures a smooth work flow (in a factory) or a particular traffic pattern in a service or the layout decision .

Objective of Layout Design

1. Facilitate attainment of product or service quality

2. Use workers and space efficiently3. Avoid bottlenecks4. Minimize unnecessary material handling

costs5. Eliminate unnecessary movement of

workers or materials6. Minimize production time or customer

service time7. Design for safety

The Need for Layout Decisions

Inefficient operations

For Example:

High CostBottlenecks

Changes in the designof products or services

The introduction of newproducts or services

Accidents

Safety hazards

BASIC PRODUCTION LAYOUT FORMATS

A process layout. A product layout. A group technology (cellular) layout. A In a fixed-position layout. Retail service layout. Office layout.

A process layout

A process layout (also called a job-shop or functional layout) is a format in which similar equipment or functions are grouped together, such as all lathes in one area and all stamping machines in another. A part being worked on then travels, according to the established sequence of operations, from area to area, where the proper machines are located for each operation.

The most common approach to developing a process layout is to arrange departments consisting of like processes in a way that optimizes their relative placement. For example, the departments in a low-volume toy factory might consist of the shipping and receiving department, the plastic molding and stamping department, the metal forming department, the sewing department, and the painting department

Interdepartmental flow

Building dimentions & departments.

Interdepartmental Flow Graph with Number of Annual Movements.

Cost matrix – first solution

Revised Interdepartmental Flow Chart (Only interdepartmental flow with effect on cost is depicted.)

Cost matrix –second solution

A feasible solution.

A Product layout

A product layout (also called a flow-shop layout) is one in which equipment or work processes are arranged according to the progressive steps by which the product is made. The path for each part is, in effect, a straight line. Production lines for shoes, chemical plants, and car washes are all product layouts.

In product layout, equipment or departments are dedicated to a particular product line, duplicate equipment is employed to avoid backtracking, and a straight-line flow of material movement is achievable. Adopting a product layout makes sense when the batch size of a given product or part is large relative to the number of different products or parts produced.

ASSEMBLY L INES Assembly lines are a special case of product

layout. In a general sense, the term assembly line refers to progressive assembly linked by some material handling device.

ASSEMBLY-LINE BALANCING Though primarily a scheduling issue,

assembly-line balancing often has implications for layout. This would occur when, for balance purposes, workstation size or the number used would have to be physically modified.

Assembly lines

Designing Product Layouts

Step 1: Identify tasks & immediate predecessors Step 2: Determine the desired output rate Step 3: Calculate the cycle time Step 4: Compute the theoretical minimum number of workstations Step 5: Assign tasks to workstations (balance the line) Step 6: Compute efficiency, idle time & balance delay

Step 1: Identify Tasks & Immediate Predecessors

Example 10.4 Vicki's Pizzeria and the Precedence DiagramImmediate Task Time

Work Element Task Description Predecessor (secondsA Roll dough None 50B Place on cardboard backing A 5C Sprinkle cheese B 25D Spread Sauce C 15E Add pepperoni D 12F Add sausage D 10G Add mushrooms D 15H Shrinkwrap pizza E,F,G 18I Pack in box H 15

Total task time 165

Layout Calculations

Step 2: Determine output rate Vicki needs to produce 60 pizzas per hour

Step 3: Determine cycle time The amount of time each workstation is allowed

to complete its tasks

Limited by the bottleneck task (the longest task in a process):

sec./unit 60

units/hr 60

sec/min 60x min/hr 60

units/hroutput desired

sec./day time available)(sec./unit time Cycle

hourper pizzasor units/hr, 72sec./unit 50

sec./hr. 3600

time task bottleneck

time availableoutput Maximum

Layout Calculations (continued)

Step 4: Compute the theoretical minimum number of stations TM = number of stations needed to

achieve 100% efficiency (every second is used)

Always round up (no partial workstations)

Serves as a lower bound for our analysis

stations 3or 2.75,

nsec/statio 60

seconds 165

time cycle

times taskTM

Layout Calculations (continued)

Step 5: Assign tasks to workstations Start at the first station & choose the longest eligible task

following precedence relationships Continue adding the longest eligible task that fits without going

over the desired cycle time When no additional tasks can be added within the desired cycle

time, begin assigning tasks to the next workstation until finishedWorkstation Eligible task Task Selected Task time Idle time

A A 50 10

B B 5 5

C C 25 35

D D 15 20

E, F, G G 15 5

E, F E 12 48

F F 10 38

H H 18 20

I I 15 5

1

2

3

Last Layout Calculation

Step 6: Compute efficiency and balance delay Efficiency (%) is the ratio of total

productive time divided by total time

Balance delay (%) is the amount by which the line falls short of 100%

91.7%100sec. 60x stations 3

sec. 165

NC

t (%) Efficiency

8.3%91.7%100%delay Balance

A Group technology(cellular) A group technology (cellular) layout groups

dissimilar machines into work centers (or cells) to work on products that have similar shapes and processing requirements. A group technology (GT) layout is similar to a process layout in that cells are designed to perform a specific set of processes, and it is similar to a product layout in that the cells are dedicated to a limited range of products. (Group technology also refers to the parts classification and coding system used to specify machine types that go into a cell.)

Fixed position layout

In a fixed-position layout, the product (by virtue of its bulk or weight) remains at one location. Manufacturing equipment is moved to the product rather than vice versa. Construction sites and movie lots are examples of this format.

Cont…

● ● ● Fixed-position layout is characterized by a relatively low number of production units in comparison with process and product layout formats. In developing a fixed position layout, visualize the product as the hub of a wheel with materials and equipment arranged concentrically around the production point in their order of use and movement difficulty.

Retail service layout

The objective of a retail service layout (as is found in stores, banks, and restaurants) is to maximize net profit per square foot of store space. A company that has been very successful in leveraging every inch of its layout space to achieve this objective is Taco Bell Restaurants. Taco Bell store layouts used in 1986 and from 1991 to the present. The nature of the layout changes reflects actions required to support the company’s value strategy of speed and low prices.

Taco Bell Restaurant Floor Plans

Alternative store layouts.

Office layout

● ● ● The trend in office layout is toward more open offices, with personal work spaces separated only by low divider walls. Companies have removed fixed walls to foster greater communication and teamwork. (See, for example, the Breakthrough Box titled In New Drug Labs, Porches and Huddle Zones. Signs, symbols, and artifacts, as discussed in the section on service layout, are possibly even more important in office layout than in retailing.

Thank you