ASD - The extra dimension in software engineering share

Design Automation for Software Engineers

InCose evening lecture

ASD – The extra dimension in Software Engineering Peter van de Velde Customer Solutions Architect

October 20, 2011

ASD - The extra dimension in software engineering | InCose evening lecture | Copyright 2011 Verum Software Technologies 2

Agenda

-  System engineering vs. software engineering -  ASD -  What is it -  Let’s see it (the real thing - live)


System Engineering Keywords on InCose site

-  Complex systems -  Decomposition into subsystems -  Composition: system = sum of subsystems -  Way of working and thinking -  System of Interest - Context Diagram -  Model Based System Engineering (MBSE) -  Internal subsystem dependencies and behaviour -  External subsystem dependencies and behaviour


System Engineering versus Software Engineering

-  Decomposition into subsystems -  Engineering of subsystem in software =

Software Engineering -  Same keywords as system engineering

-  Model Based Software Engineering using Analytical Software Design (ASD)


Nothing New…

Design Model

Design Verification

Design Implementation

Images from Lusas Engineering Analysis


Software Design with Formal Verification

Design Model

Design Verification

Design Implementation


Source Code

Model-Driven Development

Traditional model Is the model correct ?

Is the source code

correct ?


Next Generation Model-Driven Development

Source Code

ASD model

§  ASD Models are: §  Precise §  Complete §  Traceable §  Correct



Formal model and verification

Generate formal model

Design Errors

Source Code

ASD model


✔


✔


ASD:Suite guarantees equivalence

EU patent 1749264 Hong Kong patent HK 1104100

Formal model and verification

Generate formal model

Design Errors

Source Code

ASD model

Generate source code from verified

model


§  MISRA C §  C++ §  C# §  Java

✔

§  ASD Models are: §  Precise §  Complete §  Traceable


Let’s see it

-  Live presentation -  or

-  Do it yourself demo with a free trial version and demonstration example Free 30-day trial: http://www.verum.com/product/30-day-trial.aspx


The Domain for ASD

ASD can be used to model: -  Control (concurrent or reactive system) -  Model the state of a system and all discrete events

that can happen and reaction to it (behaviour) -  Work-flow (business interaction) -  Where are we in the process, which tasks have been

performed, and which still needed etc. -  Product life cycle management -  Status of a product (new, backorder, delivered, paid,

returned, etc.) -  Etc.


The Domain for ASD Discrete Decisions and Actions (1)

Decision based on discrete events: -  A method call -  Init, Print, GetStatus, Delete, Terminate, etc.,

-  A notification (internal or external) -  Task completion, cancellation, status update, time out,

interrupt, etc. -  A result of data interpretation -  Discrete values: true <> false, red<>green<>blue -  Evaluation function: needCredibilityCheck(order.value)


The Domain for ASD Discrete Decisions and Actions (2)

Discrete events resulting in executing actions: -  A method call to a used component -  A notification to the calling component -  An internal state change in any combination


ASD In a Nutshell

Analytical Software Design is a -  Set of methods -  Way of working -  Platform


ASD Set of Methods

-  Model driven development based on Sequence-Based Specifications (SBS)

-  Component-based -  Separation of interfaces and implementation -  Described in interface and design models

-  Formal verification -  Brute force calculation of all possible execution

scenarios based on CSP (Communicating Sequential Processes) and FDR (Finite Divergence Refinement)


ASD Way of Working

-  Make a context diagram -  Define external interfaces (interface models) -  Make a decomposition -  Define internal interfaces (interface models) and

component (design models) -  Verify components -  Generate code -  Build -  Integrate and test


ASD Way of Working Product Development Approach

-  Can be used in an incremental way of working -  Complete interfaces, extend implementation function

by function -  Extend interface and implementation function by

function -  Suitable for agile development

-  Can be used in waterfall way of working

-  On-line training is example of incremental approach


ASD Way of Working Impact

-  ASD adds a structural way of working -  If you are used to that: hardly any changes -  If not: ASD is an evolution, no revolution

-  ASD may change the way of thinking -  Programming -> Engineering -  Object Oriented -> Component-Based


ASD Way of Working Context Diagram (Software)

Alarm

System

Console HAL

Sensor HAL

Siren HAL

External Interface of AlarmSystem

External Interface of Siren

External Interface of Sensor


ASD Way of Working Decomposition

-  Decomposition of AlarmSystem is rather simple: 1 component AlarmSystem

-  (example more complex decomposition is included)


ASD Way of Working Component Diagram

Service of AlarmSystem described in Interface Model

Service of Siren described in Interface Model

Component AlarmSystem described in Design Model

Non ASD Component (handwritten code)

Non ASD Component (handwritten code)


ASD decomposition Bigger example


IAlarm

Alarm

ISiren ISensor

ASD Way of Working Verify components (1)

-  Confirmation that a component is correct and complete with respect to its surrounding interface specifications

-  Answers the questions: -  Are the interfaces well-formed? -  Is the design well-formed? -  Does the design maintain its

interface contracts?

⊑


ASD Way of Working Verify components (2)

-  Checks modelling errors -  Checks invariants -  Checks guard completeness -  Checks state variable ranges -  Checks for illegal behaviour (typically caused by

race-conditions) -  Checks for potential queue problems

-  Checks for dead/livelocks -  Checks for deterministic design -  Checks for interface compliance


ASD Platform

-  Integrated tool ASD:Suite -  Edit models (documentation, specification, design) -  Code generation (implementation: languages: C, C+

+ , C# and Java) -  Model verification* (interactive visual debugging)

-  ASD:Runtime -  A downloadable software package that enables the

generated code to run on various software platforms. -  Implements the ASD execution semantics.

-  *Boehm: verification := building the system right; validation := building the right system


ASD Platform Generated Code and ASD:RunTime


Questions


-  Thank you for your attention

-  For more information

-  Visit www.verum.com or community.verum.com -  Mail to [email protected] -  Register for a free ASD workshop

Design Automation for Software Engineers

The Power to Create Software Solutions

SUCCEED! VERIFY DESIGN

ASD - The extra dimension in software engineering share

Technology

Transcript of ASD - The extra dimension in software engineering share