Transcript Summary of Problem

Making Interoperability
Specifications Easier to
Understand
Tim Benson
[email protected]
© 2006 Abies Ltd
Interoperability is Difficult
• Shared meaning between computers requires
shared understanding between all human
participants including domain experts
• Domain experts do not understand technical
interoperability specifications
• Misunderstandings create errors
• Errors increase costs and hit profits
© Abies Ltd 2006
Errors Multiply
• No of errors = P x C x N
P = probability of misunderstanding a particular part
of the specification
• depends on difficulty of language and knowledge
(domain and technical) of participants
C = complexity - the total number of choices to be
made
• depends on length of specification and numbers of
options allowed
N = number of times that each choice is made
• depends on number of sites and individuals
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Traditional Approach
Domain
Expert
Software
Developer
Integration
Engineer
Domain
Expert
Software
Developer
Does Not Scale
© Abies Ltd 2006
© Abies Ltd 2006
Requirement
• A precise and detailed specification
which can be understood, reviewed,
checked and signed off by:
– Domain experts
– Software developers
– Integration engineers
• Basis of an agreed contract
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Feedback and Iteration
1. Scope and
Objectives
Project Lifecycle
2. Process Analysis
and Design
Technology-independent
3. Logical Design
Specification
Domain expert sign-off
4. Implementable
Specification
Technology-specific
Specification (HL7 V2 or V3)
5. Software Application
Development
6. Testing and
Certification
Implementation
(where the real money is spent)
7. User Education,
Data Migration, Go-Live
8. Support and
Maintenance
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Logical Design Specifications
•
•
•
•
Comprehensive and complete within scope
Stringent, detailed, rigorous and precise
Coherent (fits together) and consistent throughout
Comprehensible – can be understood and reviewed
by all stakeholders
– Domain Experts (with some help)
– Integration Engineers
– Application Software Implementers
• Composed from reusable elements
• Computer-readable (e.g. XMI)
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Logical Design Model
• Logical Design Model is UML model with
class and activity diagrams
• Each transaction is one view into the model
– rendered as one or more class diagrams
– transactions cross activity diagram swim lanes
• Includes glossary
– single source for data element definitions
• Output as diagrams, HTML and XMI (XML)
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Lab Results Example
• Following slides show:
– Logical Design Model
• based on PMEP and ELINCS
– Lab Results RMIM (NHS CFH)
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© Abies Ltd 2006
Laboratory Results RMIM
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How it works
Logical
Logical Design
Design Model
Specification
Conventional Method
Reference
Model
eg HL7 V3 RIM
Technology
Specific
Specification
Normative
Specification
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Model and Specifications
Logical Design
Specification
Logical
Design
Model
Logical Design
Specification
Logical Design
Specification
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Technology-specific
Specifications
Technologyspecific
Specification 1
Logical
Design
Specificatio
n
Technologyspecific
Specification 2
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Shared Understanding
Integration
Engineer
Domain
Expert
Domain
Expert
Domain
Expert
Software
Developer
Logical Design
Specification
semantically
equivalent
Software
Developer
Software
Developer
© Abies Ltd 2006
Technology-specific
Specification
Danish Progress
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Making Interoperability Specifications
Easier to Understand
Any Questions
Tim Benson
[email protected]
© 2006 Abies Ltd