11/13/2015 ieng 471 facilities planning 1 ieng 471 - lecture 03 product & process design
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IENG 471 - Lecture 03
Product & Process Design
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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
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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
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Example: Manual Juicer
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Example: Manual Juicer
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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
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Example: Manual Juicer
Materials of construction:Aluminum (sandcast) bodyRubber feet
Cost of the artifact:$ 0.32 in aluminum$ 0.04 in rubber $ ??? in labor, shipping, packaging, etc.
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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
Example: Manual Juicer
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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 .
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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
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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
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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)
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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
0101Trim, sand, inspect
0101Trim, sand, inspect
A1
A2
Plastic Bag
4031
SA1
I1
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Standard OPC Symbols
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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
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Example: Manual Juicer Precedence Diagram
4001
4021
4002
4003
4004
0101
0102
0101
0101
0101
A1 A2
4031
SA1
I10100
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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)
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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
Meredith, J. R. & Mantel, S. J. (2006)
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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
Meredith, J. R. & Mantel, S. J. (2006)
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PERT: Activity on Node Notation
Early Start (ES) Early Finish (EF)
Activity Duration (D)
Late Start (LS) Late Finish (LF)
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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
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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
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PERT: Critical Path Example
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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
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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!
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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
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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