11/13/2015 ieng 471 facilities planning 1 ieng 471 - lecture 03 product & process design

04/20/23 IENG 471 Facilities Planning 1

IENG 471 - Lecture 03

Product & Process Design


Product Design

Must meet the needs of the customerQFD

Must be communicated (internally)Product Drawings (Assembly, Detail)Parts ListPart Structure

Indented BOM covers both the parts list and part structure


Indented Bill of Materials

A “BOM” is a document that:Lists all parts in an assemblyShows the quantity of all componentsAllows for the roll-up of costsShows the sequence of assembly

Each indentation shows the components of the sub-assembly


Example: Manual Juicer



Function of the product:Obtain seed-free juice from produce

Principle(s) of operation:Lever (Class 2) to provide pressureGrating to stop seeds Gravity to drain the juice



Materials of construction:Aluminum (sandcast) bodyRubber feet

Cost of the artifact:$ 0.32 in aluminum$ 0.04 in rubber $ ??? in labor, shipping, packaging, etc.


Indented BOM & Cost Roll-up:

(1) Juicer Assembly $ 0.36

(1) Body Sub Assembly $ 0.18

(1) Body Casting $ 0.14

(4) Rubber Feet $ 0.01

(1) Strainer Casting $ 0.05

(1) Lever Casting $ 0.10

(1) Hinge Pin $ 0.03



BOM Example in Excel

Quantity Description Cost

1 Juicer Assembly $0.36 . .

. 1 Body Sub-Assembly . $0.18 .

. . 1 Body Casting . . $0.14

. . 4 Rubber Feet . . $0.01

. 1 Strainer Casting . $0.05 .

. 1 Lever Casting . $0.10 .

. 1 Hinge Pin . $0.03 .


Process Design

Steps in Process Identification1. Define elemental operations

2. Identify alternative process(es) for each operation

3. Analyze alternative processes for each operation

4. Standardize processes for each operation

5. Evaluate alternative processes for overall production

6. Select processes for overall production


Routing ExampleROUTING

PART NAME: Shaft, Vise PREPARED BY: DATE:

PART NUMBER: DRAWING NUMBER: GT CODE:

MATERIAL: Brass LABOR RATE: TOTAL COST:

Process Parameters Estimated

Op. Speed Feed Depth Labor Setup

No. Operation Description ft/min rpm ipr ipm in. Machine hrs. hrs Cost Remarks

1 Cut material from bar 150 band saw 0.10 0.10 Leave extra for machining

2 Face 1st end of shaft 150 900 0.005 lathe 0.20 0.05 take minimal needed for cleanup

3 Face 2nd end of shaft 150 900 0.005 lathe 0.20 0.05 cut to length per print

4 Turn diameter to length, rough 150 900 0.015 lathe 0.20 0.05 leave .03 for finish cut

5 Turn diameter to length, finish 150 900 0.005 lathe 0.10

6 Cut groove 150 900 0.005 lathe 0.20 0.05

7 Chamfer end of shaft 150 900 0.005 lathe 0.10 0.05

8 Turn diameter to length, rough 150 900 0.015 lathe 0.20 0.05 leave .03 for finish cut

9 Turn diameter to length, finish 150 900 0.005 lathe 0.10

10 Chamfer end of shaft 150 900 0.005 lathe 0.10 0.05

11 Center drill end of shaft 150 900 0.010 lathe 0.10 0.10

12 Drill hole in end 150 900 0.010 lathe 0.10 0.05 drill extra deep

13 Tap hole lathe 0.10 0.10 hand tap, lots of oil

14 Center drill for cross hole 200 1200 0.006 mill 0.10 0.10

15 Drill cross hole 200 1200 0.006 mill 0.10 0.05

16 Chamfer cross hole 100 600 0.005 mill 0.05 0.05 both sides


Operation Process Chart

Circles represent operations Number in circle represents standard operation Prefix in circle identifies:

Subassemblies (SA) – child levelsAssemblies (A) – parent level in this view

Circles are annotated with operation description

Boxes represent inspections Number in box represents standard operation Boxes are annotated with inspection description

Arcs (lines) represent component(s) Arcs are annotated with part number & description for

introduced components (See Figure 2.12 in text, p. 44)


Example: Manual Juicer Operations-Process Chart

Body Casting

4001

Rubber Feet

4021

Strainer Casting

4002

Lever Casting

4003

Hinge Pin

4004

0101Trim, sand, inspect

0102Trim, inspect 0101

Trim, sand, inspect



A1

A2

Plastic Bag

4031

SA1

I1


Standard OPC Symbols


Process Design Result

The result of the process design can be a precedence diagram:Take the OPC and turn it on its’ side.

Connect the component arcs with a single operation (START), and you have a Precedence Diagram

The precedence diagram can be converted to a PERT chart for SCHEDULE DESIGN


Example: Manual Juicer Precedence Diagram

4001

4021

4002

4003

4004

0101

0102

0101

0101

0101

A1 A2

4031

SA1

I10100

18

PERT: Scheduling Terminology

Activity - A specific task or set of tasks that are required by the project, use up resources, and take time to complete

Event - The result of completing one or more activities. An identifiable end state occurring at a particular time. Events use no resources.

Network - The combination of all activities and events define the project and the activity precedence relationships

Meredith, J. R. & Mantel, S. J. (2006)

04/20/23 IENG 471 Facilities Planning

19

PERT: Scheduling Terminology

Path - The series of connected activities (or intermediate events) between any two events in a network

Critical - Activities, events, or paths which, if delayed, will delay the completion of the project. A project’s critical path is understood to mean that sequence of critical activities that connect the project’s start event to its finish event



20

PERT: Activity-on-Node Network Fundamentals

Y and Z are preceded by X

Y and Z can begin at thesame time, if you wish

(2)

A is preceded by nothingB is preceded by AC is preceded by B

(1)

J

J, K, & L can all begin atthe same time, if you wish(they need not occursimultaneously)

All (J, K, L) must becompleted before M canbegin

but

AA

(3)

(4)

Z is preceded by X and Y

AA is preceded by X and Y



21

PERT: Activity on Node Notation

Early Start (ES) Early Finish (EF)

Activity Duration (D)

Late Start (LS) Late Finish (LF)


22

PERT: Calculating ES and EF

Forward Pass Through Network: Move left to right, covering each simultaneous

activity in order ES = maximum of EF for all immediate predecessor

activities (0 for START activity) EF = ES + Duration

Critical Time = EF of the END activity


23

PERT: Calculating LS and LF

Backward Pass Through Network: Move right to left, covering each simultaneous

activity in order LF = minimum of LS for all immediate successor

activities (Critical Time for END activity) LS = LF – Duration

Slack (Float) Time: LS – ES Note: Slack = 0 for Critical Activities


PERT: Critical Path Example

24

A 1

B 3

C 3

D 2

F 1

E 4

G 1

H 1 Z 2

1 4 4 5 5 6

1 4

1 3 4 8

8 9

3 6 6 7 7 8

1 4

2 4 4 8

8 9 9 11

9 11

0 1

0 1

Critical Time = 11 sec

Critical Path = A, C, E, H, ZSlack B, F, G = 2 sec

Slack D = 1 sec


25

PERT: Critical Path Management

CP are those activities where ES = LS Any delay in these activities will delay production! Wrong to say that these activities are the most

important, though:Frequently, activities with slack are put off until too late if

not monitored!Other paths may be near-critical, and will also delay the

project if not monitored!



Tying Critical Path to Facilities

Critical Path is connected to Makespan If this were a repetitive operation environment:

Makespan is the total time for a single, physical unit to go through all operations

In manufacturing, the time difference between the start and finish of a sequence of jobs or tasks

In health care, the duration of a patient’s medical experience for a treatment episode

Team exerciseSuppose that you had to schedule people to produce a

product What would you do to operations on the CP? What might you do with non-CP operations?

Skorin-Kapov, J. & A. J. Vakharia


Questions & Issues

HW 2: Hands on assignment to develop:

BOMOperations Process ChartPrecedence Diagram

Team exerciseTeams must be different from Project Teams

Semi-randomly assigned

4 people per team (5 people, if necessary)Other tools are in MIL Lab (IER 310)

Leave the tools there, but OK to take the product parts

11/13/2015 ieng 471 facilities planning 1 ieng 471 - lecture 03 product & process design

Documents

facilities planning

bom example

body casting

lever casting

manual juicerieng

strainer casting

body subassembly

body sub assembly