1 ©B. Henderson-Sellers SEMAT 2010 SEMAT Position Statement March 17, 2010 Brian Henderson-Sellers...

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


Overview

1st My “philosophy” for SE and SEMAT

2nd Some urgent issues in SE Method and Theory


Philosophy for SEMAT

Engineering applies science to real world problem solving

No theory of its own - relies on theories in other, more fundamental disciplines


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


Ignorance of existing theories is dangerous

Perils of ignoring theories

Tacoma Narrows Bridge collapse – a civil engineering lesson!


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


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.)


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


SE Method and Theory

• My proposal

• Quantify and codify

Basics

Methods

Validation

Validation

Methods

BASICS


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


Detour to metamodelling (one option)

endeavour

method

metamodelActivity

WorkUnit

Task Technique

* *

methodologies assessment quality tools


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


A simplified architecture

WorkProducts

Producers

WorkUnits

Stages

Languages& notations

create

aredocumented

using

produce&maintain

perform

providemacro organizationto the methodology


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


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


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


Part of a possible SEMAT metamodel

Universal

CompetencyActivityProducer Stage

StateGraphTask

Practice

Alpha

Pattern

WorkProduct

Ensure “Risk/Uncertainty” & “Quality” included

Mostly powertype patterns


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


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)


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


Outreach

• Agree and employ standards

• Propagate new vision

“Quantify and Codify”

Validation

Methods

BASICS

1 ©B. Henderson-Sellers SEMAT 2010 SEMAT Position Statement March 17, 2010 Brian Henderson-Sellers...

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