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1©B. Henderson-Sellers SEMAT 2010
SEMAT Position Statement
March 17, 2010
Brian Henderson-Sellers PhD, DSc, MASCE, FIMA, FACS, FIEAust, CPEng
Director, COTAR
Faculty of Engineering & Information Technology
University of Technology, Sydney
2©B. Henderson-Sellers SEMAT 2010
Overview
1st My “philosophy” for SE and SEMAT
2nd Some urgent issues in SE Method and Theory
3©B. Henderson-Sellers SEMAT 2010
Philosophy for SEMAT
Engineering applies science to real world problem solving
No theory of its own - relies on theories in other, more fundamental disciplines
4©B. Henderson-Sellers SEMAT 2010
Relevant established theories
• Category and set theory: mathematics• Estimation theory: statistics and signal
processing• Measurement theory: mathematics• Systems theory : ecology and
meteorology• Organizational theory: behavioural
psychology• Operational research: mathematics
5©B. Henderson-Sellers SEMAT 2010
Ignorance of existing theories is dangerous
Perils of ignoring theories
Tacoma Narrows Bridge collapse – a civil engineering lesson!
6©B. Henderson-Sellers SEMAT 2010
Task
Activity
Process
Life CycleProcess Group
Step
Activity
WorkDefinition
Task
Activity
Process
NoteList
(a) (b) (c)
+Child0..*
(d) WorkUnit
ProcessTechniqueTask
+StartTime+EndTime+Duration
+Parent0..1
+Context1
+Component0..*
SE has no agreed set of concepts
SE has no accepted terminology
7©B. Henderson-Sellers SEMAT 2010
In practice
• What is frequently called a process is just a set of ordered steps (a.k.a. procedure)
• Problem with many current ISO software engineering standards. (Arguably a process also includes resources, people etc.)
• Move away from Tayloresque factory processes to flexible processes that consider local situational context (risks, skills, culture etc.)
8©B. Henderson-Sellers SEMAT 2010
SE – still a proto-discipline
SE – today is an empirically-based proto-discipline has almost no data
Analogy can be drawn with the state of in business and management BEFORE their quality revolutions
9©B. Henderson-Sellers SEMAT 2010
SE Method and Theory
• My proposal
• Quantify and codify
Basics
Methods
Validation
Validation
Methods
BASICS
10©B. Henderson-Sellers SEMAT 2010
Start with basics
• Basics layer has a reliance on logic and mathematics - e.g. set theory, category theory, VDM
• Measurement framework is a vital element• Concepts (the “kernel language”) depicted
using formal mathematics or less formal visualizations based on this e.g. ontological structures, metamodels
11©B. Henderson-Sellers SEMAT 2010
Detour to metamodelling (one option)
endeavour
method
metamodelActivity
WorkUnit
Task Technique
* *
methodologies assessment quality tools
12©B. Henderson-Sellers SEMAT 2010
A metamodel
• is simply a model (of models)
• is often the core of CASE/CAME tools. Thus, implicitly accepted by users as being a “rule set”
• can provide an extensible framework across multiple abstraction levels
13©B. Henderson-Sellers SEMAT 2010
A simplified architecture
WorkProducts
Producers
WorkUnits
Stages
Languages& notations
create
aredocumented
using
produce&maintain
perform
providemacro organizationto the methodology
14©B. Henderson-Sellers SEMAT 2010
The ISO/IEC 24744 metamodel MethodologyElement
+Purpose+MinCapabilityLevel
WorkUnitKind
+Description
WorkProductKind
+Definition
ModelUnitKind
+Name
Template Resource
+Name
Language
+Name
Notation
+Expression
Constraint
+Description+MinCapabilityLevel
Outcome
EndeavourElement
+StartTime+EndTime+Duration
WorkUnit
+CreationTime+LastChangeTime+Status
WorkProduct
ModelUnit
+Description
GuidelineProducerKind
+Name
ProducerStage
StageKind
pow
erty
pes
15©B. Henderson-Sellers SEMAT 2010
Powertypes solve non-transitivity
project
method
metamodel
“MySystem”RequirementsSpecification
“MySystem”RequirementsSpecification
DocumentDocument
RequirementsSpecificationDocument
RequirementsSpecificationDocument
DocumentKind
DocumentKind
TitleVersion
TitleVersion
NameMustBeApprovedNameMustBeApproved
TitleVersion
TitleVersion
Req. Spec. DocumentMust be approved: yesReq. Spec. DocumentMust be approved: yes
“MySystem” Req. Spec.Version 1.5
“MySystem” Req. Spec.Version 1.5
16©B. Henderson-Sellers SEMAT 2010
More simply
Powertype pattern Resource (a metamodel class)
Clabject in method (a.k.a. process
model)
powertype “instantiation”
regular class instantiation
Metamodel domain
Method domain
Object in method
17©B. Henderson-Sellers SEMAT 2010
Part of a possible SEMAT metamodel
Universal
CompetencyActivityProducer Stage
StateGraphTask
Practice
Alpha
Pattern
WorkProduct
Ensure “Risk/Uncertainty” & “Quality” included
Mostly powertype patterns
18©B. Henderson-Sellers SEMAT 2010
Having established the basics
• How to create level 2 (Methods)
• Best candidate Situational Method Engineering
• SME uses method fragments, each defined in to be conformant to some Level 1 definition
• Ontological descriptions may be useful here
• Detour to SME - a good example
Project characteristics
Selection and Assemblyof Method Fragments
into Situational Method
Methodbase
Project characteristics
Selection and Assemblyof Method Fragments
into Situational Method
Methodbase
19©B. Henderson-Sellers SEMAT 2010
SME in a nutshell
Method fragmentsRepository
Methodology Instance
Step 2: Project Manager
Construction Guidelines
uses
Metamodel
conformant to
conformant to
Methodology M
Step 1: Method engineer conformant to
(e.g. ISO/IEC 24744)
20©B. Henderson-Sellers SEMAT 2010
Level 3 is also vital
• Engineering disciplines are observationally-validated
• Good quality data are vital to provide empirical evidence for “good practice”
• Accept validated concepts into “body of knowledge” (link to SWEBOK)
• Eschew “proof by assertion” – common today in SE
21©B. Henderson-Sellers SEMAT 2010
Outreach
• Agree and employ standards
• Propagate new vision
“Quantify and Codify”
Validation
Methods
BASICS
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