Marcos Esterman, Associate ProfessorIndustrial and Systems Engineering DepartmentRochester Institute of Technologymarcos.esterman@rit.edu

Multidisciplinary Senior Design I

System Design

Agenda

Tuesday End-State Deliverables Functional Analysis

Example Team Project Work

Concept Generation Morphological Analysis

Thursday Concept Generation

Develop Alternatives Engineering Analysis Concept Selection

END-STATE DELIVERABLES – WEEK 6

Functional DecompositionVentilate

UnresponsivePerson (UP)

Access UP’s Airway Circulate Air

Intake Air Transport Air Control Air

Control Air Pressure

Sense Pressure

Change Pressure

Control Air Volume

Sense Air Volume

Change Air Volume

Control Breathing Rate

Sense Breathing rate

Change Breathing rate

Purify Air

Monitor Physiological Data

Sense Physiological Data

Transmit Physiological Data

Alternatives ConsideredCriteria

Have a modern look and feel - + + + + + +

Is Light weight + S - + - + -Is Small - + + S + - +

Is Easy to Use S + + + - S SHas Long-Lasting Portable Power S - - + S + -

Low Cost Functional Prototype S + S + - + -

Low UMC for Final Design + - + - S + SAlert user of the

following data: XXX - - + + + + +Measure Oxygen Levels - + S + + + -

Measure CO2 Levels + - + S + S +Transfer Data Wirelessly S - - S S - +Assist Human to Breathe + - S + S S S

Integrates into CPR Process + - + + + - -

Does not interfere with the following life-saving

measures: XXX+ S + + - S S

Improves air quality delivered to patient S - - S S - +

Is safe - + S S - + SIs reliable S - + + - + -

Needs to use principles in patents #5,211,170 and

# 5,398,676 S - S S + + S

Needs to be consistent with FDA 510K Approval + + - S + S -

+ 7 7 9 11 8 10 6- 5 10 5 1 6 4 7

DATU

M

Selected Concept Updates: Electronic controls

(decrease size/more options)

Smaller pump Reliable and smaller

battery Additions:

Ability to monitor and record vitals

Pulse oximeter feedback Voice alerts/instructions Carbon dioxide sensor

Architecture

Risk Assessment

Risk Item Effect Cause

Likelihood

Severity

Importance Action to Minimize Risk Owner

Date of Completion

1over heating

damaged components; total system failure

electronic components; environment; mis-use; upkeep

2 3 6 basic thermal analysis; provide safety cautions Dan week 9- MSD1

2Integration of hardware and software together

non-workable prototype

using devices from different companies that don't function together

2 2 4

plan and read specs on all technical components; test components compatability Derek week 9- MSD1

3inputs do not match outputs

failing to meet FDA requirements

programing and calibration errors

2 1 2quality testing of design

Chris/ Kennedy MSD2

4battery integration in system

underperforming; fire hazard

battery failure; not meeting engineering specs

1 2 2check with experts on how to manage battery functionality Eric MSD2

5 Durability failure

components breaking; failure of system

components malfunctioning during usage

2 3 6perform vibration testing; perform environmental testing Ryan MSD2

Tech Concerns

There is no shame in this being a large list, especially at this stage.Demonstrates that you are being realistic.

Test Plan (First Cut)

Test Pump Test Verify Mass Flow Rate

Test Mass Flow Sensor Verify Readings Match Pump Test Results

Test Pressure Sensor Compare against Flow Characteristics chart of the

Pressure sensor. Test User Interface

Verify ease of use

SYSTEM DESIGN

Considerations

Physical Decomposition Subsystem Identification

Functional Decomposition Specification Decomposition

Need to flow-down specifications

FUNCTIONAL ANALYSIS

What is a function?

Function – active verb, noun A clear, reproducible relationship between the available

input and the desired out of the product, independent of any particular form

Examples: Make Copies, Chop Beans, Clip Nails

Otto, K., Wood, Kristin L., Product Design: Techniques in Reverse Engineering and New Product Development, Prentice Hall, Upper Saddle, NJ 2001, pp. 152 – 151. 13

Product Represented as a Functional System

Energy

Material

Information

Energy

Material

Information

Example

What is the function of this?

Product Represented as a Functional System

Energy

Material

Information

Energy

Material

Information

Open CanCan

Sealed Can

Can, Lid, Contents

Opened Can

Energy could be manual, electric, kinetic, potential, etc. depending on solution, so typically only worry about flows that will not change

What is the function? What flows will not change?

Decompose Function

Open Can

Access Can

Locate Can

Secure Can

Separate Lid

Puncture Can

Grip Can Edge

Pierce Can

Rotate Can

Access Contents

HOW

WHY

Subtract and Operate – Bill of Materials

Part # Part Name Category Function

1Casing Structural component

Holds, protects, and supports internal and external components

2 Guide bar Support element Guides lever arm and can3 Magnet Support element Holds can lid4 Geared wheel Output Rotates can5 Cutting blade Output Cuts though can lid6 Lever arm Structural component Holds blade and magnet; on/off switch7 Motor Input Rotates the geared wheel

8Medium gear Output

Converts the electrical energy into the horizontal mechanical energy

9Large gear Transmission Reduces speed of rotation and provides

more torque; connects to geared wheel10 Switch Power supply Completes circuit; on/off switch11 Power cord Power supply Supplies power to motor

Source: http://gicl.cs.drexel.edu/wiki/Can_Opener

Generating a Hardware Tree Can Also be Very Helpful

Subtract & Operate

Part # Part Name

1Casing

2 Guide bar3 Magnet4 Geared wheel5 Cutting blade6 Lever arm7 Motor

8Medium gear

9Large gear

10 Switch11 Power cord

Open Can

Access Can

Locate Can

Secure Can

Separate Lid

Puncture Can

Grip Can Edge

Pierce Can

Rotate Can

Access Contents

Protect Opener

Capture Lid

Added Functions

ActuateOpener

Subtract & Operate Method

Bottom-up approach Assumes product or product concept exists

Steps Remove one component of the assembly

Literally or Figuratively “Operate” system through its full range Analyze effect Deduce the sub-function of the missing component Repeat for all components Modify function tree

Otto, K., Wood, Kristin L., Product Design: Techniques in Reverse Engineering and New Product Development, Prentice Hall, Upper Saddle, NJ 2001, Chapter 5. 19

Modified Functional Decomposition

Open Can

Access Can

Locate Can Secure Can

Actuate Opener Separate Lid

Puncture Can

Grip Can Edge Pierce Can

Rotate Can

Transmit Electrical Energy

Covert Electrical Energy to Rotation

Covert Rotation to Torque

Capture Lid Access Contents Protect Opener

Process Flow Can Also be Helpful

Access Can

Secure Can

Actuate Opener

Separate Lid

Capture Lid

Access Contents

Grasp Can

Attach Opener

Apply Lever

PierceCan

RotateHandle

Transmit Torque

Capture Lid

Access Content

High-Level View

Low-Level View

FUNCTIONAL ANALYSIS WORKSHOP

Exercise - Define your project’s top level function (5 minutes) Remember that the top level function should

manipulate material, energy and/or information that is external to your system

23

Functional Decomposition Exercise – (20 minutes) Generate the 1st level (& 2nd Level, if possible)

of Decomposition for your top level-function Ensure that it is as solution independent as

possible

24

Subtract & Operate Exercise – (20 minutes) Develop a hardware tree/bill of materials

based on an existing solution or a benchmarked solution Go to level that makes sense

Determine if the function the component is performing is Represented in the function decomposition –or- Is connected to a function in your decomposition

Modify function tree

25

CONCEPT GENERATION

26

27

5-Step Process (Ulrich & Eppinger, pg. 100)

Clarify the Problem Start from Product Definition Decomposition Prioritize

Search Externally Lead users Experts Patents Benchmarking

Search Internally dfX Analysis Field Feedback Institutional Knowledge Supply Chain

Explore Systematically Classification Tree Combination Tree Morphological Analysis TRIZ

Reflect on Process & Solutions

1. Clarify the Problem

5. Reflect onSolutions

4. ExploreSystematically

3. SearchInternally

2. SearchExternally

Sub-problems

ExistingConcepts

NewConcepts

IntegratedSolutions

Secrets of Concept Generation Employ many techniques Focus on values / functions Avoid premature closure Generate several alternatives

“Sky High” “Challenging technology” “Low Risk”

Screen ideas systematically e.g., Pugh selection process

Ishii, 200428

Morphology Study of shape

and form Morph. Analysis

Systematic study to analyze the possible shape and form

Morphological Diagram Example: Potato

Harvesting Machine

Pahl and BeitzMorphological Analysis

29

Bathroom Scale Example Expand Functions to manageable sub-functions

MeasureWeight

SupportSubject

Conv.Mass to Signal

IndicateSignal

HoldPartsTogether

Start with Functional Diagram

Ishii, 200430

Bathroom Scale

MeasureWeight

SupportSubject

Conv.Mass to Signal

IndicateSignal

HoldPartsTogether

Spring StrainGauge

CountMolecules

CornFlakes

Dial Voice Sound DigitalDisplay

Plate Box Bubble

Screws Glue

Use the Function Diagram to Generate Concepts

Ishii, 200431

Feasible (Conventional) Bathroom Scale

MeasureWeight

SupportSubject

Conv.Mass to Signal

IndicateSignal

HoldPartsTogether

Spring StrainGauge

CountMolecules

CornFlakes

Dial Voice Sound DigitalDisplay

Plate Box Bubble

Screws Glue

Generate Feasible Solutions

Ishii, 200432

“Sharper Image” Bathroom Scale

MeasureWeight

SupportSubject

Conv.Mass to Signal

IndicateSignal

HoldPartsTogether

Screws

Spring StrainGauge

CountMolecules

CornFlakes

Dial Voice Sound DigitalDisplay

Plate Box Bubble

Glue

Generate “Sky high” Ideas too...

Ishii, 200433

MorphChart

34

Douglas Axtell, Don Moran,Jason Stanbro, Jim Vermeire, 0303-786 & 0303-788 Class Project, 2010

Can Opener Example

Can Opener ExampleAccess Can

Actuate Opener

Puncture Can

Rotate Can

Capture Lid

Access Contents

Protect Opener

grasp

Concept Generation Exercise – Morphological Table(30 minutes)

Start generating your morphological table and finish for homework

37

Desired Output

Function Tree 2-3 Layers of Decomposition

Subsystem Identification Should be based both on existing artifact and

functional analysis Specification Flow-down

If you identify functional modules and/or subsystems, need to understand how you will assess them

Conceptually no different than what you did at the system-level

This will set you up for developing good solution alternatives