Applying UML to TestStand and LabVIEW Matthew Kennedy Engineering Manager [email protected]

Applying UML to TestStand and LabVIEW

Matthew KennedyEngineering Manager

[email protected]

www.bloomy.com© 2003 Bloomy Controls Inc.

Agenda

Software project problems Why UML? Useful UML tools for TestStand and LabVIEW Conclusion Resources

* This is not a UML course. Just not enough time.


Software Project Problems

Software functionality Requirements definition

End users and programmers exist in different worlds and speak different languages Requirements get lost or misunderstood

Software programmers don’t have clear requirements, skip design, and go straight to code development


Minimize Software Project Cost

“Just complete the software THEN fix it.”

Three simple rules:1. State requirements2. Create system design3. Code to the design

Units Stage

.1-.2 Requirements

.5 Design

1 Coding

2 Unit test

5 Acceptance test

20 Maintenance1 unit=Effort required to detect and repair a error during coding


Where Does UML Come In?

UML can help software programmers and project engineers to: Define customer requirements Create basic designs

Set of notation and meta-model language tools Defined notation Applicable to many programming languages Makes programmers put pencil to paper and diagram/plan

systems


Useful UML Tools for LabVIEW and TestStand

Use cases Interaction diagrams

Sequence diagrams Activity diagrams


Stage 1: Requirements

Use case First step toward defining a software system A set of scenarios tied together by a common user

goal Describes what system must do


Use Case Example

Example: Load UUT for testMain success scenario:

1. Operator picks up UUT from rack2. Operator checks UUT socket clear3. Operator inserts UUT into test fixture4. Operator starts test5. Fixture locks down UUT6. Test begins

Extension 5a. Fixture fails to lock down

5a1. Eject UUT5a2. Reset test system5a3. System request maintenance

• Communicate requirements

•A set of scenarios tied together by a common user goal

•Plain language

Load UUTfor Test

Actor


Use Case Diagram – ExampleSet Product

LimitsTransport

UUT Rack toValidation

Load UUT forTest

Update YieldReports

ReevaluateLimits/SPC

Test UUT

UUT Fails toLoad

Design Engineer

Manufacturing Tech

Test Operator

Quality Engineer

<<extend>>


Use Cases – Final Thought

Of all UML tools, use cases are arguably the most important

Key to ensure a successful requirements stage Actors are not always easy to identify

Actor could be the test system itself, a sequence, etc. Meant to be simple but detailed enough to

manage project scope


Stage 2: Design

Sequence diagram Describes how groups of objects or processes behave in a

sequential and concurrent manner Typically defines a single use case

Activity diagram A state of doing something Describes sequence of activity

State diagram Describes all possible states that can occur in a system


Sequence Diagram Example

Test SocketLoad Window

DAQHIL

TestSequence

[No Latch && <5 it.]Latch UUT

Objects/Processes

Message

[No Latch] RequestMaitenance

Latch UUT

TerminationRoutine[Latch]Begin Test

Return

Self-Call

DAQHIL

Initialize Hardware

Creation

Latch UUTFor Test


Activity Diagram

Latch UUTFor Test

Initalize DAQ Hardware

Prompt User to InsertUUTand

request SN

Test UUT

Read LatchSwitch

Display SafetyWarning Message

[System Latched]

Prompt Userfor Maintenance

Sequential Process Model MainSequence

SwimLanes

Fork

Join

Branch

Merge

End

[Else]

Guard


State Diagram

Open DAQ Driver References

Latch UUTand check for confirmation______________________

do/command latchdo/check latch indication

Update GUI indicating UUTLatch Progress

Abort Routine

Flash Red LED

Flash Green LED

System Latched

Close DAQ Driver Reference

User Manual Abort/Abort

[No

La

tch

&&

Use

r R

eq

ue

st R

etr

y]/R

ep

ea

t

[else

]/La

tch[noLatch &&< 5 trys]/retry

(La

tch S

tatu

s)/Co

ntin

ue

[Else]

/Display GUI

event(arguements)[condition]/action

[Latched][n

o L

atch

]

Start

Transition

State

Activity

self-transition[E

lse

]

[no

La

tch

]

Read LatchSwitch Activity


Stage 3: Coding

Software design must be implemented Obvious implementations

State diagrams: LabVIEW state machinesSequence diagrams: TestStand sequence

LabVIEW dataflow programming Sequence structuresActivity diagrams: LabVIEW state machines TestStand sequences

Using a state diagram does not mean you must use a LabVIEW state machine


Fancy Flowcharts?

Isn’t UML just another flowchart?

Widely accepted standard Intuitive to use Many end users already have familiarity with UML

Instantly start talking the same language Plenty of resources to help Flowcharts and more with standardized notation


More UML Uses

Tools for programming graphical object orientated code in LabVIEW – GOOP Useful for class diagrams, package and collaborations

diagrams Some projects require merging traditional text-based

OOP languages and LabVIEW UML design tools do not necessarily determine implementation Mix and match the appropriate tools and ADEs


Tools to Help

Rational Rose Visio – UML toolkit New LabVIEW state machine wizard Any word processor: Use case development


Lessons Learned

Keep use cases detailed Avoid using language-specific information of software

design in use cases Use swimlanes with activity diagrams to assist in

modularizing TestStand sequence development Finish state machine diagram before writing LabVIEW

code Use only what you need

Unnecessary to use every diagram tool to adequately design a software system


Conclusion

UML is an industry-accepted standard for developing software architectures

More and more people are becoming aware of the benefits of using UML

UML is an excellent tool for developing LabVIEW and TestStand architectures BEFORE coding

Use appropriate UML tools UML can save time and money by preventing costly

rework


Recommended Reading

UML Distilled Second Edition, Martin Fowler and Kendall Scott

Managing Software Requirements a Unified Approach, Dean Leffingwell and Don Widring

The Unified Modeling Language Guide, Grady Booch, Ivar Jacobson, James Rumbaugh

Writing Effective Use Cases, Alistair Cockburn


Web Resources

Use-cases.org foruse.com UML.org Rational.com


About Bloomy Controls

Test, measurement, automation, and control specialists since 1991

Systems integration, software development, and training provider

NI Select Integrator and Certified Training Center 3 Certified LabVIEW Architects 8 Certified LabVIEW Developers 1 Certified TestStand Architect 2 Certified TestStand Developers 8 Certified Professional Instructors

Offices in Windsor, CT; Milford, MA; and Mahwah, NJ


Contact Bloomy Controls

Email [email protected] Write or visit

CT, Western MA, Eastern NY:

Eastern MA, RI, Northern New England:

Greater NYC, NJ:

839 Marshall Phelps Rd. 100 Medway Rd., Ste 202Windsor, CT 06095 Milford, MA 01757 Mahwah, NJ(860) 298-9925 (508) 902-0054 (201) 818-0117

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Applying UML to TestStand and LabVIEW Matthew Kennedy Engineering Manager [email protected]