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GROUP MEMBERS

• Ahsen Ali 11-IE-06• Mohsin Tariq 11-IE-22• Shahbaz Farid 11-IE-35

Chapter#06

Layout Planning Models and Design Algorithms

Facility Layout

• Facility layout is simply the way a facility is arranged in order to maximize processes that are not only efficient but effective towards the overall organizational goal.

• It consists of two levels:– Block layout– Detailed layout

Block Layout

• Block layout shows the location, shape, and size of each planning department.

• Block layout is concerned primarily with macro flows in the facility.

Detailed Layout

• Detailed layout shows the exact location of all the equipment, work benches and storage areas within each department.

• Detailed layout is concerned with micro flows in the facility.

Which layout comes first!

• First, we must obtain the basic requirement of each department (such as space requirement, shape constraints, etc) and then develop a set of alternative block layouts.

• Once the desirable block layout is identified, the analyst can then develop a detailed layout of each department.

Layout Procedures

• Many procedures are available• Broadly classified:– Construction layout method• It involves developing a new layout “from scratch”

– Improvement layout method• Generating layout alternatives by doing improvements

in an existing layout

Apple’s Plant Layout Procedure

Apple’s Plant Layout Procedure

Reed’s Plant Layout Procedure

Reed’s Plant Layout Procedure• Most important– Prepare layout planning chart

• Layout planning chart incorporates the following:– Flow process, including operations, transportation,

storage and inspections– Standard times for each operations–Machine selection and balance–Manpower selection and balance–Material handling requirements

Layout Planning Chart

Systematic Layout Planning• A well known procedural solution approach for

the layout problem is the Systematic Layout Planning (SLP), which is developed in the early 1970s by Muther

• It consists of four phases:– determining the location of the area where facilities

will be laid out– establishing general overall layout– establishing detailed layout plans– installing the selected layout

Activity Relationship Chart

Relationship Diagram

• Relationship diagram position the activities spatially.

• Proximities are typically used to reflect the relationship between pair of activities

• Relationship diagram are usually two-dimensional

Relationship Diagram

Space Requirement Diagram

• It involves the determination of the amount of space to be assigned to each activity

• Once the space assignments have been made, space templates are developed for each planning department, and space is “hung on the relationship diagram” to obtain the space relationship diagram

Space Requirement Diagram

Alternative Block Layout

Algorithmic Approaches

• It helps the analyst to develop and improve the layout.

• It provides the objective criteria to facilitate the evaluation of various layout alternatives that emerge in the process.

Algorithm Classification

• Layout algorithm can be classified on the type of input data.

• Qualitative data (Relationship Chart)• Quantitative data (To and From Chart)• It can be classified w.r.t Objective Function.

a) Distance based objective

b) Adjacency based objective

Distance Based Objective

Adjacency Based Objective

Modeling Techniques for Algorithm

• There are many method/techniques which are used in various layout Algorithms.

• Here we will discuss only two:

a) Pairwise Exchange Method

b) Graph Based Method

Department Shapes and Main Aisles

• Attaining good department shapes is an important consideration in finalizing block layout

• Irregular department shapes leads to irregular main aisles

• For efficient material handling, safety and evacuation in emergency

Main aisle should connect all the departments in a facility with

• Minimum travel• Minimum number of turns• Minimum jog overs• Controlling department shapes is straight forward for

rectangular departments obtained with BLOCPLAN and MIP

• It is straight-forward to define and measure shape of rectangle

• It is ratio of longer side to its shorter side

• Non rectangular shapes those obtained with CRAFT and MULTIPLE

• Shape measurement and control is not straight forward for given two alternatives but “similar shape” for the same department

• One alternative may be regarded as acceptable while other regarded as poor

• First measure obtained by dividing the area of the smallest enclosing rectangle (SER) by area of department

• The second measure is obtained by dividing the longer side of SER by its shortest side

• Third measure based on observation, given an object with fixed area the perimeter of the object generally increases as its shape become more irregular

• Measure the shape of a department by dividing its perimeter by its area

• It is difficult to predict reasonable value for it

• Above ratio is normalized as follow

• If ideal shape for a department is square, then ideal shape factor

S*=(P/A)*=4√A/A=4/√A

• Normalized Shape Factor F is equal to

F=S/S*=P/A/4/√A=P/4√A

• If a department is square shape then we obtain

F=1.0 otherwise F>1.0

• Reasonable shapes are obtained if

1≤F ≤1.4

First measure Second measure

For figure a,b,c,d

a) =1 a) = 4

b) 25/16=1.5625 b) =1

c) =1.5625 c) =1

d) =1.5625 d) =1

Third measure perimeter

a) =1.25 a) =20

b)=1.25 b) =20

c) 1.5 c) =24

d) 1.625 d) =26

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