2 Dechazelles Fraboulet

Prepared by G. Fraboulet, Seditec and P. de Chazelles, Airbus

Presented by: Gaëlle Fraboulet, Seditec

Use ofUse ofUse ofUse ofRequirement Engineering DisciplineRequirement Engineering DisciplineRequirement Engineering DisciplineRequirement Engineering Discipline

in support of A/C Engineeringin support of A/C Engineeringin support of A/C Engineeringin support of A/C Engineering


ObjectivesObjectivesObjectivesObjectives

l Some definitions of Requirement Engineering

l Highlight motivation for using Requirement Engineering

l Understand Requirement Engineering process across levels

l Understand the application of Requirement Engineering to

Product and Sub-product

l First conclusions on Deployment of Requirement Engineering

for Airbus A380


Requirement EngineeringRequirement EngineeringRequirement EngineeringRequirement Engineering


What is Requirement Engineering?What is Requirement Engineering?What is Requirement Engineering?What is Requirement Engineering?

l Discipline which addresses requirements as objects all along

a system development process

l Discipline that provides a set of processes to identify and

engineer requirements, not only manage but also analyse,

validate , trace...


What is a requirement?What is a requirement?What is a requirement?What is a requirement?

REQUIREMENT

RATIONALE

ASSUMPTION

VERIFICATIONPROCEDURE

RISK

TRADE_OFF

PRODUCT

STAKEHOLDER

Supported_by

Emitted_by

Conditioned_by

Associated_with

Result_from

Allocated_to

Verified_by


Requirement structure & richnessRequirement structure & richnessRequirement structure & richnessRequirement structure & richness

Element Definition Minimumelements

Example

1 Actor of action Subject of the sentence Mandatory Developer

2.Condition foraction

Conditions under whichthe action takes place

When producingrequirements in Worddocument

3. Action A verb Mandatory shall use4. Constraints ofaction Qualification of the action

5. Object ofaction

Thing acted upon by theactor Mandatory iSEF CARE Macro V5

6. ObjectRefinement Qualification of the object Or any iSEF tool agreed

by BNE

7. ActionRefinement

Further qualification ofthe action

8. Other Non requirement material

Example:BNEY-SER-038-1 When producing requirements in Word document, Developer shall use iSEF CARE Macro V5 or any iSEF tool agreed by BNE.

Most requirements should have 5-7 elements


Motivation for usingMotivation for usingMotivation for usingMotivation for usingRequirement EngineeringRequirement EngineeringRequirement EngineeringRequirement Engineering


Requirements Engineering eases the V&V and certification process

Ä By supporting a rigorous , traceable means of compliance

(Requirements management, traceability, verification)

Ä By contributing to fulfil ARP 4754 recommendations

(ARP 4754: Certification Considerations for Highly-Integrated

or Complex Aircraft Systems)

MotivationMotivationMotivationMotivation


Failure Condition, Effects, Classification, Safety Objectives

System Development ProcessSafety Assessment ProcessCertification

Item Requirements

Safety Processes

Results

System Implementation

Aircraft Level Functional Requirements

Allocation of Aircraft Functions to Systems

Development of System Architecture

Aircraft Functions

Implementation

Allocation of Item Requirements to Hardware & Software

Physical System

Considerations for Highly Integrated or Considerations for Highly Integrated or Considerations for Highly Integrated or Considerations for Highly Integrated or Complex Aircraft Systems (ARP4754)Complex Aircraft Systems (ARP4754)Complex Aircraft Systems (ARP4754)Complex Aircraft Systems (ARP4754)

Systems Functions

Failure Condition, Effects, Classification, Safety Objectives

System Architecture

Architectural Requirements


Identified expectations for Systems Identified expectations for Systems Identified expectations for Systems Identified expectations for Systems Development from ARP4754Development from ARP4754Development from ARP4754Development from ARP4754

l Added design discipline and development structure to ensure that safety and operational requirements are fully realized and substantiated (cf & 1.1 Purpose)

l Functional requirements to obtain the desired performance of the system under the conditions specified. They are a combination ofcustomer desires, operational constraints, regulatory restrictions, and implementation realities. (cf &5.2.2 Functional Requirements)

l Traceability one of the mean for validation: The requirement should either be traceable to a parent requirement, or by identification of the specific design decision or data from which the requirement was derived.

Ä Airbus has developed and deployed a C.A.R.E Capability that covers Process/Method/Tools as a means to comply with ARP4754 requirements


RequirementRequirementRequirementRequirement FlowdownFlowdownFlowdownFlowdownacross Development levelsacross Development levelsacross Development levelsacross Development levels


Engineering Process Flow in support of A/C Engineering Process Flow in support of A/C Engineering Process Flow in support of A/C Engineering Process Flow in support of A/C Product Development according to EIA 632Product Development according to EIA 632Product Development according to EIA 632Product Development according to EIA 632

A/CDesign process

Feedback

Other StakeholdersRequirements

Feedback

Feedback




Feedback

Airlinesneeds

AssignedSpecified

Requirements

AssignedSpecified

Requirements

AssignedSpecified

Requirements Major CompDesign process

ItemDesign process

Sub-itemDesign process

Level N+1

Level N

Level N-1


RepresentationRepresentationRepresentationRepresentation of of of of complexcomplexcomplexcomplex productproductproductproductbreakdownbreakdownbreakdownbreakdown (EIA 632) (EIA 632) (EIA 632) (EIA 632)

Productionproducts

Testproducts

Complex product

Developmentproducts

Deploymentproducts

Trainingproducts

Supportproducts

End-products Enabling-products

End-Product

Main Comp.or system

Main Comp.or system

Main Comp.or system

Main Comp.or system

Disposalproducts

Performsoperationalfunctions

Performs associated life-cycle process

Functions

Consists of

This representation of complex product apply at any level where product decomposition occurs!


Relation between development level Relation between development level Relation between development level Relation between development level and product breakdownand product breakdownand product breakdownand product breakdown

A/CDesign process

Airlinesneeds

Major CompDesign process

ItemDesign process

Sub-itemDesign process

Productionproducts

Testproducts

Complexproduct

Developmentproducts

Deploymentproducts

Trainingproducts

Supportproducts

End-products Enabling-products

End-Product

Main Comp.or system

Main Comp.or system

Main Comp.or system

Main Comp.or system

Disposalproducts

The result of architecting the product at one level

is a set of sub-products description at lower level


Program

A/Ccomponents

Aircraft

A380 Requirements cascade objectiveA380 Requirements cascade objectiveA380 Requirements cascade objectiveA380 Requirements cascade objective


V&V StrategyV&V StrategyV&V StrategyV&V Strategy

• V&V activity depends on the assurance level required.

• The V&V assurance level assigned is based on :

• Certification consideration based on the most severe failure condition classification set for safety objectives for each function

• Maturity consideration based on events, which could lead to flight interruption or a delay.

• Example: For a system that could be level D for safety issue, if the novelty risk is high, the V&V assurance level becomes B’.


Application of Requirement EngineeringApplication of Requirement EngineeringApplication of Requirement EngineeringApplication of Requirement Engineeringto Product and Subto Product and Subto Product and Subto Product and Sub----productsproductsproductsproducts


Acquirer Requirements

PhysicalSolution

representation

OtherStakeholder

Requirements

SpecifiedRequirements

Assigned to

Assigned to

Assigned to

drive

Derived Technical

Requirements

drivesource of

Specified by

Design Solution

TechnicalRequirements

Assigned to

Logicalsolution

representation

RequirementsRequirements flowdownflowdown attached to attached to each product or subeach product or sub--product (EIA 632)product (EIA 632)


1 –ACCOMODATE

PAYLOAD

2 –MOVE FROM DEPARTURE TO ARRIVAL

- 3 –ACCOMODATE COMMON

RESSOURCES

4 – SUPPORT OPERATION, MAINTENANC

E AND AIRLINE

PROMOTION

5 – ENSURESAFETY / SECURITY

OF OPERATIONS

A/CFunctionalArchitecture

√√ √√ √√

√√ √√ √√

√√ √√ √√ √√

√√ √√ √√

√√ √√ √√

FDD

√√

√√

√√

√√

√√

TLSRD or TLStRD

TLRs

FRD

A/C Physical Architecture

PRODUCT BREAKDOWN


Requirements Flow across LayersRequirements Flow across LayersRequirements Flow across LayersRequirements Flow across LayersApplication to A380 Development ProcessApplication to A380 Development ProcessApplication to A380 Development ProcessApplication to A380 Development Process

TLSRD

FRD FDD

SRD SRDSDD SDD

PTS PTS

A/C Level

« Systems/structure » LevelSystem A System B

Structure element C

TLRs


ConclusionConclusionConclusionConclusion

-- ReminderReminder-- Status & Status & wayforwardwayforward


Strategy for Establishment and Strategy for Establishment and Deployment of Requirement EngineeringDeployment of Requirement Engineering

• ObservationRequirement Engineering is a new discipline that requires time to be understood and deployed.

• StrategyFocus has been made on how to engineer a requirement rather thanhow to manage requirements.

•Impact:Priority has been given to the process and method deployment rather than tool deployment.

•Schedule

ØSept. 1999: First Draft of process established commonly by previous Airbus partners: Aerospatial (France), Daimler-Chrysler Airbus (Germany), BAe Systems (UK), CASA (Spain)ØMid 2000: First Word MacroØEarly 2001: Decision to deploy widely Process and MacroØUntil today: Requirement Management tool under deployment


Status & way forwardStatus & way forward

• Current Status•Requirement Engineering is now a corner stone of Aircraft Engineering at all levels for the A380

•Way forward•Continuous improvement and training are necessary to move from a document oriented approach to a Requirement Engineering as part of System Engineering approach

2 Dechazelles Fraboulet

Technology

Transcript of 2 Dechazelles Fraboulet