The Impossibility of Requirements

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The Impossibility of Requirements

• Malcolm Eva

Eva Business Learning
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Requirements Proverbs

• Delivery is not necessarily the best time to
  discover the user requirements.
• Urban Wisdom.

is'al mujarrib wala tas'al Tabib. If you
want to know what it feels like, ask a patient,
not a doctor. Arabic Proverb.
The Americans spent millions of dollars
developing a pen that could write upside down in
zero gravity. The Russians gave their cosmonauts
crayons
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The Requirements Engineering Process
Requirements Catalogue
Track changes Management of requirements
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STABILITY

• CONFLICTS AND INCONSISTENCIES
• EVOLVING USER UNDERSTANDING
• BUSINESS CHANGE

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Your finger, stupid, or the danger of speaking
to domain experts

• Actual meaning of place names
• Senegal means That's my boat
• Yucatan means Go away.
• (apocryphal tale only)

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What can you see?
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Problems of Tacit Knowledge

• Imparting skills
• New and future systems
• Anomalous States of Knowledge (Belkin) (ASK)
• Taken-for-granted (Grice) (TFG)
• Front-story/Back-story
• Problems of Memory
• Recall
• Recognition

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Making the tacit explicit (1)
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Making the tacit explicit (2)
TACIT
EXPLICIT
ARTICULATE
Apprentice
Codify
Observe
Report and Record
Recount
Disseminate
Enact
Identify values
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ELICITATION METHODS FOR TACIT KNOWLEDGE

• Apprenticing Shadowing, Protocol Analysis
• Recount Story-telling, Scenario
• Enact Prototype
• Identify values Personal Construct Theory
  (Repertory Grids, Card Sorts, Laddering)

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Fit Between Knowledge Type and Elicitation Method
Explicit Knowledge
Taken for granted
Skills
Future systems
KEY YY very good match Y Can help N will
not help
YY
Y
N
Y
1-1 Interviews
Shadowing
YY
YY
YY
N
Workshops
Y
N
N
YY
YY
YY
YY
YY
Prototyping
Scenario
YY
YY
N
YY
Protocol Analysis
YY
YY
YY
N
(ACRE - Acquisition of Requirements, Maiden and
Rugg, 1996)