ISE 312 Chapter Six - Binghamton



ISE 312 Chapter 12 & 13 (Sule) Plant and Office Layout: Conventional Approach

Spring Semester

Plant & Office Layout Development

1) Determine the area required for each work center. (Space requirements & allowances for aisles)

2) Establish a From-To (quantitative) or Relationship (qualitative) chart.

3) Develop a graphical representation of the From-To or Relationship chart.

4) Develop an Evaluation chart.

5) Develop templates to represent each area.

6 ) Arrange templates to represent each area.

Example From-To Chart: (Average flow of units per day).

Machine A B C D E

A 10 50

B 25 30

C 20

D 25

Relationship chart (From-To chart) describes qualitatively the degree of closeness the analyst feels exist.

Factors Impacting Relationship (REL) Code:

1) Quantity of Flow

2) Cost of Material Handling

3) Equipment used in Material Handling

4) Need for close communication

5) Need to Share Same Personnel

6) Need to Share Equipment

7) Separation for Noise, Danger, Chemicals, Fumes, Radiation, or Explosives

Example: Relationship Priority Codes:

Code Priority Value

A Absolutely Necessary 4

E Especially Important 3

I Important 2

O Ordinary 1

U Unimportant 0

X Undesirable -1 (maybe noisy area, -10 for severity)

Relationship Chart Example:

Nodes PR WA OF TR FS MA LR SR Area (ft2)

1) Production (PR) --- A(4) E(3) A(4) E(3) A(4) E(3) E(3) 4,800

2) Warehouse (WR) ---- O(1) O(1) U(0) O(1) U(0) A(4) 3,050

3) Office (O) --- U(0) O(1) O(1) U(0) O(1) 2,400

4) Tool-Room (TR) --- O(1) A(4) U(0) U(0) 1,150

5) Food Services (FS) --- U(0) U(0) U(0) 750

6) Maintenance (MA) --- U(0) O(1) 1,000

7) Locker Room (LR) --- U(0) 600

8) Shipping/Receiving Room (SR) --- 1,900

(Symmetrical about the diagonal)

ISE 312 Chapter 12 & 13 (Sule) Plant and Office Layout: Conventional Approach

Spring Semester

Mileage Chart Format for Relationship (REL) Chart

[pic]

ISE 312 Chapter 12 & 13 (Sule) Plant and Office Layout: Conventional Approach

Spring Semester

Develop a Graphical Representation for a Layout using the REL Chart:

Nodal Representation:

Work centers become nodes and the number of lines between two nodes represents the required closeness between the nodes.

Objective: Arrange the nodes so that there are a minimum number of areas crossed when going from one department to another with the frequencies indicated by a decoded REL-chart.

Steps for developing a Nodal Representation:

> Find total measure of importance of a department. Convert Relationship chart to value chart.

The measure of importance of each area on a value chart, which ascertains the degree of closeness one department has with all other areas, is obtained by adding the row and column values for that department together.

Example of converting REL chart to value chart: Add relationship values to all other departments (add Row + Column). This becomes the measure of importance of each area.

PR = (row1) 4 + 3 + 4 + 3 + 4 + 3 + 3 = 24

WR = (row2) 1 + 1 + 0 + 1 + 0 + 4 + (col WR) 4 = 11

O = (row 3) 0 + 1 + 1 + 0 + 1+ (col OF) 3 + 1 = 7

TR = (row 4) 1 + 4 + 0 + 0 + (col TR) 4 + 1 + 0 = 10

FS = (row 5) 0 + 0 + 0 + (col FS) 3 + 0 + 1 + 1 = 5

MA = (row 6) 0 + 1 + (col MA) 4 +1 + 1 + 4 + 0 = 11

LR = (row 7) 0 + (col LR) 3 + 0 + 0 + 0 + 0 + 0 = 3

SR = (row 8) (col SR) 3 + 4 + 1 + 0 + 0 + 1 + 0 = 9

Nodal Placement:

Highest Measure of Importance goes in the middle of the Nodal Representation.

Locate 4 (absolutely necessary) relationships around the middle department.

Departments with next highest measure of importance are placed around the 4-relationship departments.

Continue the sequence with 3-relationship departments until all departments are used.

Review the diagram and adjust the position of departments to satisfy closeness in between.

Note: Closeness of a department with 3-relationships is more important than one with 2-relationships. The basic objective is to develop an arrangement in which departmental crossovers are at a minimum.

A good nodal representation has the fewest lines crossing the least number of departments.

See Nodal Representation Example (next page):

1) Highest total is 24 for PR place production in the middle.

2) 4-Relationships with PR is 2,4, and 6. Place these departments around the sides.

3) Look ahead for 4-relationships with 2, 4, and 6. Here 8 has a 4-relationship with 2. Place it next to 2.

The basic objective is to develop an arrangement in which departmental crossovers are at a minimum when travel between departments is made based on the value chart.

ISE 312 Chapter 12 & 13 (Sule) Plant and Office Layout: Conventional Approach

Spring Semester

[pic] [pic]

Nodal Representation Nodal Representation with Potential Problem

Develop an Evaluation chart to provide a measure of effectiveness of the nodal arrangement.

> Allows different arrangements to be evaluated.

> Lowest value is measure of best arrangement.

Method:

Convert nodal representation into a semi-scaled Grid Representation. For each department, the necessary

area is equated to the approximate number of blocks required. Place the individual departments within

the grid arrangement, represented by the necessary blocks for each.

The closeness measure is equal to the shortest rectilinear distance between two areas multiplied by the

value of the relationship between those two departments. The grand total gives the measure of

effectiveness of the nodal diagram. (example: shortest rect.-distance between 2 & 6 is 3 blocks)

Block Calculations for Grid Representation: (Use 400 square feet (20x20) = 1 block for this grid).

Department Area Blocks Department Area Blocks

PR 4800 12 FS 750 2

WR 3050 8 MA 1000 2

O 2400 6 LR 600 2

TR 1150 3 SR 1900 5

Total number of blocks = 40; thus, limiting overall dimensions to 5 x 8 blocks.

Place departments in grid according to the nodal representation, keeping shape regular as possible.

ISE 312 Chapter 12 & 13 (Sule) Plant and Office Layout: Conventional Approach

Spring Semester

[pic]

Grid Representation

Evaluate with respect to distances & departments crossings with closeness measure.

Multiply by Grid Representation closeness measure by REL Chart values:

Evaluation Chart:

Nodes PR WA OF TR FS MA LR SR Row Value

1) Production (PR) --- 0 0 0 0 0 0 0 0

2) Warehouse (WR) ---- 1 x 1 0 x 1 4 x 0 3 x 1 4 x 0 0 x 4 4

3) Office (O) --- 3 x 0 0 x 1 3 x 1 2 x 0 0 x 1 3

4) Tool-Room (TR) --- 4 x 1 0 x 4 2 x 0 2 x 0 4

5) Food Services (FS) --- 2 x 0 0 x 0 4 x 0 0

6) Maintenance (MA) --- 2 x 0 5 x 1 5

7) Locker Room (LR) --- 6 x 0 0

8) Shipping/Receiving Room (SR) ---

Effectiveness Measure = Total 16

Note:

The shape of the grid can be changed without significantly affecting the results as long as the shape is designed with practically in mind rather than for the purpose of defeating the procedure.

ISE 312 Chapter 12 & 13 (Sule) Plant and Office Layout: Conventional Approach

Spring Semester

Step Five: Convert Grid to a scale model using templates.

> The Grid is only an approximation of the required area. Enlarge or reduce Grid to meet specifications.

[pic]

Departmental Templates

> Templates are laid out according to the grid. Arrange templates to represent each area.

Initial Layout: [pic]

ISE 312 Chapter 12 & 13 (Sule) Plant and Office Layout: Conventional Approach

Spring Semester

Step Six: Small adjustments are made to produce a smooth layout from the irregular initial layout.

> The Grid has already approximated the layout, the task should be minor adjustments for a starting solution.

[pic]

Final Layout

Next step is a detailed drawing with location of machines, operators, aisles, & MHS. Scale ¼” = 1 foot.

3 Phases in Presenting the Layout:

> Preparing a neat & organized facility layout & plot plan.

> Written report describing the benefits & high points.

> Oral presentation integrating the report & plans.

Office Layout

Use REL charts with needed square feet; use same methods as plant layout.

Planning Activities:

1) Purchase Date

2) Scheduled Construction

3) Equipment purchased & installed

4) Hire new workers

Computer-Aided Plant Layout

Evaluation of all the combinations of departments & their locations. Other critical objectives.

Mathematical Programming: m locations to n departments assigned; minimize movement cost.

Heuristics: produces good sub-optimal solutions while handling large layout problems.

Probabilistic Approaches: Simulation using all feasible layouts (stop when no improvements made).

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download