IE550 05/04/23

Design for Production in Existing Facilities (DPEF)

Richard A. WyskThe Pennsylvania State University

IE550 Manufacturing Systems

IE550 05/04/23

Design for Production in Existing Facilities (DPEF)

Given: » a product design,» the expected production requirements for the

new product,» a set of production resources and the current

configuration (production lines, cells, etc.), and

» the expected requirements for the products currently being produced,

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Design for Production in Existing Facilities (con’t)

Answer the following questions:» Can the new product be produced in the required

quantities given the current production allocation?– if so, what are the expected production costs ?– if not, can the current production be reallocated such

that all of the production requirements can be met?– if not, can the design be modified to enable

production within the current resource structure?– if not, how should additional resources be acquired

to meet the production requirements?

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How it’s done today: Parametric-based Feature Information

Feature information (Intra-feature specifics)» Dimensions» Size Tolerances» Surface Finishes» Geometric Tolerances

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Product, Process and Production Models

Product EngineeringLibrary of featuresFeature interactions

Process EngineeringProcess / Feature linksInter-feature linkagesInter-process linkages

Production EngineeringSystem SpecificsMachine SpecificsFixture Specifics

Tool Specifics

Com m on Data Pool

ProductionEngineering

On-lineSFCS

ProductEngineering

CAD(Modeling,Analysis)

ProcessEngineering

CAPP(Aggregation,

Detailed)Design Data

ResourcesJob Status

Master ScheduleBills of Material

Process Plan

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Production Resource Constaints

Geometric Constraints Machine Constraints Jig/Fixture Constraints Tooling Constraints Process Constraints

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Key Process Planning Features

Plans based on Feature Precedence Graph

Generates AND/OR Graph Collects the resource data from

Databases Is independent of Decision Table

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Example: Threaded hole (.250-20 UNF Class 3)

Process alternatives» Drill -> Tap» Drill -> Thread cut» Drill -> Thread form

Process plans» Drill ---> NxxG00G91X@locY@locZ@locM06 NxxG01Z-@sizeF50 NxxG01Z@sizeF100

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Process Planner

IBM Compatible IBM Compatible

FeatureInformation

AND/ORGraph

DB

MachinesJigs/Fixtures

ToolingsLayout

Decision Table

Design Station Process Planning

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Processes SL-20 Turning

Center» Facing» Turning» Drilling» Reaming» Boring» Tapping» Threading

VF-0E Machining Center– Milling (Face/end-

milling)– Drilling– Reaming– Boring– Tapping– Threading– Engraving (Ball-mill)

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AND/OR Graph Generator

Creates an AND/OR Graph Representation of a process plan

Fills out Processing Node Information» PNI is used by NC code Generator

Covers MP, MT, MH and AS/RS nodes

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Example Part

•Cylindrical Part•Center Hole•Bolt Holes •Contour•Thread

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Process Plans Shop level plans

MT MT

Ml

Dr Tr1

MTMT

Tr2

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Process Plans Workstation level plans

MH MH

VF-3

SL-20 VF-0

MHMT

VF-0

Workstation #1Workstation #2

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Process Plans (cont.) Equipment Level Plans (Drilling)

Fx

Dr1

Dr2

Dr3

Dr4

Tp2

Tp3

Tp4

Tp1

Fx

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Decision Maker Contains the hierarchical constraints

» Machine» Fixture» Tool» Process» Feature

Can be updated indendent of Process Planner

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Decision Information

XXImpossible XXXRough TurningPUMA X Semi-finish TurningPUMA XX Finish TurningPUMA

XXXRough FacingPUMAXSemi-finish FacingPUMA

XXFinish FacingPUMA

Major CylinderMachine

F1XPUMAF1Z 0 < F1 < 20XFADAL 0 < F1 <16Y0 < F3+Hmn+Hc < 20Z

FixtureTTTTTTF1.9 < F1 < 2.0PUMAFFFFFFT0.4 < F3

FADALTool

T1PUMAT2 T3

T1FADALT2T3

Process

T F0.01 < F2ConditionT F0.01 < F4TFT 32 MU in. < F5

32 MU in. < F6 TFT32 MU in. < F7

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IPPE Concept

Design Model Process ModelCAD System

Process PlanningSystem

ProductionAnalysis System

Resource Model Instance

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Process Planner

IBM Compatible IBM Compatible

FeatureInformation

AND/ORGraph

MachinesJigs/Fixtures

ToolingsLayout

Decision Table

Design Station Process Planning

STEP or STEP-like PSL or PSL-like

Manufacturing Resource Model

Resource Model

Instance

Resource Model

Instance

Resource Model

Instance Resource Model

Instance

WWW

Multi-facility Planning and

Analysis

InquiriesProductionOrders

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Technological Hurdles

Process Planning» Given a part design, what are the processes, tools,

fixtures, etc. required to manufacture the part. All feasible alternatives should be explicitly represented.

Production Planning and Analysis» Given a set of production resources and a set of

production requirements with the associated process plans, how should the production be allocated among these resources in order to efficiently satisfy the requirements.

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Resource Model A set of definitions and symbolic descriptions

that are used to completely describe the individual resources in a facility as well as the possible interactions between these resources.

A resource model instance describes a specific facility and its resources.

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the time required for setup for an operation (load fixture, retreive tooling , etc.)

the time required to load and unload a product for feature operation j (chuck, fixture, etc..)

the machining/processing time for feature j

tool change time/part

idle time due to scheduling control

L/UL

tj

jsetupt

tj

m

ct

t i

L/UL m c=E(t jsetup+ t j + t j + t i + t )t P A

j

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Production time per piece

t t t t tp set l/ul m ch= + + +

•The cost associated with new tooling is also a key consideration for the designer.

•For low and medium volume products, the cost associated with tooling and setup can dominate the total product cost.

Performance Metrics

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Concept of a manufacturing system resource model [ Wysk, R.A.,

Peters, B.A., and Smith, J.S., “ A Formal Process Planning Schema for Shop

Floor Control ” ]

» Resource Model - set of definitions and symbolic descriptions that

are required to completely describe all of the individual resources in

a facility as well as the necessary interactions between these

resources

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Terminology

Resources (R) : Collection of assets in the facility directed towards the manufacture of the products. Includes equipment, tools, fixtures, transporters, and instruction sets

Locations (L): A precise physical location associated with a port and a part. Locations are used to link the transfer of parts between equipment types. Each location has an owner and a set of clients that can address that location

Ports (P): Ports are nodes in the graph defining the paths parts can follow through the facility (note: Graph shows the connections between the resources in the facilities

Arcs: Show which ports can be directly accessed from a particular port

Facilitator: A device than can move transporters between different ports on the MT system or move parts between a port on a MT system and a port on a MP

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Example...

MP 3

MP 2

MH 1

MT 1

1

2

3

4

1

2

3

4

MH 1

Ports, Locations : 1,2,3,4

Facilitator : MH1

Arcs between : 1-2, 2-1, 1-4, 4-1, 4-3, 3-4, 2-3, 3-2 ( represent connections between the resources )

Resources: MP2, MP3 (type MP) MT1 (type MT) MH1 (type MH)