1. Z556 Systems Analysis & Design
ILS Z556
Session 5

2. Using Language to Focus Thought (cf., Wood, 1997)
The language gives you a way to see:
a framework for interpreting the things you observe and
a structure of understanding you can elaborate as you learn more
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3. Our Tool—Graphical Languages
Advantages of a graphical language:
a picture is worth a 1000 words
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4. Models reveals relationship to the whole supports systemic thought
Too Big to See
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Too Small to See
reveals relationship to the whole
supports systemic thought
creates a coherent design response

5. Work Models
Graphical languages to capture knowledge about work Visual analysis , Complexity simplified, Focused understanding
Make concepts concrete for team discussion “on the same page”
Help communicate with clients
Identification of breakdowns
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6. 5 Work Models in Contextual Design
Flow model
The communication and coordination
Sequence model
The detailed work steps to achieve a goal
Artifact model
Physical things to support the work
Culture model
Constraints on the work caused by policy, culture, or values
Physical model
Physical structure of the work environment
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7. Flow Model (Beyer & Holtzblatt, 1998, p. 92, 93)
Represents the communication coordination necessary to make work happen
The work must be broken into discrete parts
How departments really coordinate work
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8. Flow Model Rules
(Beyer & Holtzblatt, 1998, p. 91)
People and organization are bubbles on the model, and are annotated with their position & responsibilities
Places appear as large boxes, annotated with their responsibilities
Communication breakdowns are shown with a lightning bolt
Flow is indicated as arrows between bubbles
Artifacts are shown in boxes on the line
People and organization are bubbles on the model, and are annotated with their position & responsibilities
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Informal communication and actions are written without a box
Automated systems and databases usually should not go on the flow (they are shown as a large box with responsibilities only when they act like a physical place or an automated person)

9. Flow Model Rules (Beyer & Holtzblatt, 1998, p. 91)
People and organization are bubbles on the model, annotated with their position & responsibilities
Flow is indicated as arrows between bubbles
Artifacts are shown in boxes on the line
Informal communication and actions are written without a box
Places appear as large boxes, annotated with their responsibilities
Automated systems and databases usually should not go on the flow (they are shown as a large box with responsibilities only when they act like a physical place or an automated person)
Communication breakdowns are shown with a lightning bolt
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10. Flow Model (B&H, p. 92) President Worker Request to - Run the business
schedule meeting
w/ president
-Meet w/ management
checks to sign U1
(Secretary)
Request for
clarification
- Ensure bills paid on time
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Requires lots
of iterations
invoices
Proposal
to proof
checks
Vendor
announcement
Marketing manager
- Produce proposal
Invoice for
services
Bulletin board

11. Specifying Processes Structured English
is based on the logical constructs of:
sequence
selection
iteration
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12. Sequence Model (see B&H p.96-101)
Supplies the low-level, step-by-step information on how work is actually done
Starts with the intent and trigger for the sequence and then lists each step in order
Four components:
the steps by which work is done
the triggers that start a set of steps
The intents that are being accomplished
The breakdowns that prohibit workers from being efficient
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13. Sequence Model - Trigger
Sequence Model – Steps
Sequence Model - Trigger
An action or the thought preceding an action
Details of the tasks depend on the scope of the group (e.g., writing a memo)
Interview Tip: Get more details rather than less
What causes the sequence of actions (May be discrete event, based on time, or less tangible)
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14. Collecting Sequences During an Interview
Triggers (that cause the sequence of actions):
may be discrete events, e.g.,???
may be based on time, e.g.,???
may be less tangible, e.g.,???
The system needs a way to tell the user there’s something to be done
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15. Sequence Model - Intent Sequence Model - Breakdown
Every sequence has a primary intent, which applies to the whole sequence
Secondary intent applies to individual or groups of steps
Where are the problems in the sequence
Interview Tip: Hesitations & Errors often show breakdowns.
Interview Tip: Ask how the system could do better.
Interview Tip: Hesitations while thinking reveal decision points in the process
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16. Sequence Model: Example
Intent:
Hiring someone
Trigger: someone quits
Review her job
Intent:
Review the
current position
Define candidates’ qualifications & job description
Advertise the job opening
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Receive applications
Intent: Eliminate
unqualified
candidates
Review applicants
Check references of selected candidates
Fewer candidates to invite on site

17. Sequence Model: Example
Set up interview dates with selected candidates
Intent: make decisions about which candidate
Choose the best candidate
Making a job offer
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Negotiate
Candidate accepts the job
Candidate denies the offer
Choose the 2nd best candidate

18. UML: Activity Diagrams— Example
Charts activity as it moves between different people/groups
Liner like the sequence model, but articulates different players like flow model
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The diagram came from:

19. Tools for Creating Diagrams
for collaboration)
(free for 5 diagrams)
($5/month)
(free plan included)
(open source)
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20. Decision Table
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21. Specifying Processes Structured English
is based on the logical constructs of:
sequence
selection
iteration
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22. Limited Entry Decision Table
When a customer wants to purchase an item, different conditions determine the actions you should take.
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23. Limited Entry Decision Table
First, identify the conditions:
Under $50?
Pays by check w/ 2 forms of ID?
Uses credit card?
Next, identify the actions
Ring up sale
Call supervisor for approval
Require a signature that matches one on the back of the card
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24. Limited Entry Decision Table
Under $50 Y N
Pays by check w/ 2 forms of ID
Uses credit card
Ring up sale X
Call supervisor for approval
Require a signature that matches one on the back of the card
conditions
actions

25. General Rule Check the number of rules
The number of answer: M (e.g., 2 for Y/N)
The number of condition: N
M = M x M x M x M (M to the nth power)
E.g., 2 = 2 x 2 x 2 = 8rules N
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26. Mixed Entry Decision Table
Regular customer? Y N
Order value $
0-49
50-99
> 100
Free shipping X
Discount given
10%
15% 5%
conditions
actions

27. Decision Tree: Hiring an Info Architect
College
degree
Formal
education in IA
Practical
exp in IA
Action
yes
Job offer
yes no
Keep app
yes
yes
Keep app no
Job
Applicant no
Reject
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yes
Keep app
yes no no
Reject
yes
Reject no no
Reject

28. Exercise: Decision Tree/Table
This is your last semester at ILS, and you are ready to look for jobs. You need to go through job postings and decide which jobs to apply for. Draw a decision tree or table with:
three conditions
three actions
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29. Exercise: Flow Model Form 4 groups (5 people each)
Develop a flow model based on the case presented in Alter’s article
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30. Modeling
What constitutes a good model?
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