comet, a case study distributed factory automation system software engineering 2000-2001 petta...

Comet, a Case Study

Distributed Factory Automation System

Software Engineering 2000-2001Petta Davide

Summary Problem description Requirements modeling

Use case model Analysis modeling

Conceptual static modelObject structuringFinite state machine modelingDynamic model

Design modelingSubsystem structuringDistributed software architectureSystem configuration

Problem DescriptionWorkstations on an assembly lineProgrammable WSs: different parts can be processed Part moving on a conveyor belt Processed in sequence Two kinds of workstations:

Receiving (the first one), shipping (the last one)Pick & place robot

AssemblyPick & place robot, assembly robot

One operation per workstationFactory operators, one per workstation

Views workstation status and alarmsProcess engineer

Creates process plan to define mfg (manufacturing) steps for a part Production manager

Creates work orders to process new parts (work order: # of parts of a type)

Robots have sensors and actuators

Problem DescriptionWorkstations on an assembly lineProgrammable WSs: different parts can be processed Part moving on a conveyor belt Processed in sequence Two kinds of workstations:

Receiving (the first one), shipping (the last one)Pick & place robot

AssemblyPick & place robot, assembly robot

One operation per workstationFactory operators, one per workstation

Views workstation status and alarmsProcess engineer

Creates process plan to define mfg (manufacturing) steps for a part

Production managerCreates work orders to process new parts (work order: # of parts of a type)

Robots have sensors and actuators

Noun Identification

Technique

Use Case ModelGrouped by actors:

Factory operatorView alarmsView workstation statusGenerate workstation status and notify (with factory robot)Generate alarm and notify (with factory robot)

Process engineerCreate/update process planCreate/update operation

Production mgrCreate/modify work orderManufacture part (with pick&place, assembly robot)

Receive partProcess part at workstationShip part

Use just-in-time algorithm: ws receive part only when ready to process

Use Case Model

View alarms

Generate ws StatusAnd Notify

View ws status

Generate AlarmAnd Notify

<<use case package>>FactoryOperatorUseCasePackage

FactoryOperator

FactoryRobot

Create/UpdateOperation

Create/UpdateProcess Plan

<<use case package>>ProcessEngineerUseCasePackage

ProcessEngineer

<<extend>>

Use Case Model

ManufacturePart

Create/ModifyWork Order

<<use case package>>ProductionManagerUseCasePackage

<<include>>

ShipPart

Process PartAt Workstation

ReceivePart

<<include>><<include>>

ProductionManager Assembly

Robot

Pick & PlaceRobot

Conceptual Static ModelIs very important for this case: it’s an information-intensive application Factory consists of WSs

Aggregate Factory class, composed of WS classesThree types of WSs: Receiving, Line, Shipping

Generalization/specialization hierarchyLine WSs have Pick&Place and Assembly robotsReceiving, shipping have only Pick&Place robots

WS generates one Status and multiple AlarmsBoth viewed from Factory Operator

Process plan defines with operations all parts of a given type

Operation defines a single step carried out at a WSWork order: number of parts to be manufactured of a given type

<<user>>Process

Engineer

<<entity>>Process

Plan

<<entity>>Operation

<<entity>>Part

<<entity>>Work Order

<<user>>Production Manager

<<aggregate>>Factory

<<composite>>Factory

Workstation

<<composite>>Shipping

Workstation

<<entity>>Alarm

<<user>>Factory Operator

<<entity>>Workstation

Status

<<composite>>Line

Workstation

<<composite>>

ReceivingWorkstation

<<externalsystem>>

AssemblyRobot

<<externalsystem>>

Pick&PlaceRobot

1 0..1

1..*

Views

*

*Views

*

*

11

1Processes

GeneratesGenerates

* 1

1..*

Creates*

1

Defines # of1..*1

1

*

Creates

11..*

Contains

Creates

1

*Defines

1

1..*

Conceptual

StaticModel

Composite classes

<<user>>ProductionManager

<<external system>>AssemblyRobot

workOrderID : StringcustomerName : String

partType: Stringquantity : Integerpriority : IntegerstartDate : Date

shipmentDate : Datestatus : WoStatusType

partType: StringpartID : String

status : PartStatusTypelocation : Stringpriority : Integer

nextOperation#:IntegerstartDate : Date

finishDate : Date

<<user>>ProcessEngineer

Classes and Their Attributes

<<entity>>ProcessPlanpartType : String

rawMaterialType:StringnumberOfSteps : Integer

<<entity>>Alarm

<<user>>FactoryOperator

<<entity>>Part

<<entity>>WorkstationStatus

<<entity>>WorkOrder

<<entity>>Operation

<<external system>>Pick&PlaceRobot

userID : Stringpassword : String

shift : IntegerfactoryArea : String


shift : Integer


engineerPrivileges:String

alarmNumber : IntegeralarmType : String

alarmMessage : String

workstationID : StringfactoryArea : String

location : Stringstate : WorkstationState

robotID : Integerstate : RobotState

robotID : Integerstate : RobotState

maxWeight : Integer

operation# : IntegeroperationName: String

workstationType:WsTypeprogramName : String

cycleTime : Integer

<<external user>>ProductionManager

System Context Model

<<system>>Factory

AutomationSystem

1..* <<external user>>FactoryOperator

<<external system>>Pick&PlaceRobot

<<external system>>AssemblyRobot

<<external user>>ProcessEngineer

1..*

1..*

1..*

1

1

1

1

1

1

Interactswith

Interactswith

Interfacesto

Interfacesto

Interactswith

One external class per actor:

Object StructuringIdea: we determine the objects that participate in each

use case dividing the system into objects:Entity objects for data storing objects:Process Plan, Operation, Work Order, Part,

Workstation Status, AlarmThey are all server corresponding server objects on collaboration diagrams

For each Human actor: user interface objectFactory Operator Interface, Production Manager Interface, Process Engineer Interface

Adding controllers objectsReceiving/Line/Shipping Workstation controllerto control manufacturing workstationEach robot has a controller and its mfg operations are downloaded from the Factory Automation System

Finite State Machine ModelingThere is a state-dependent object: the WS controllerMore in detail, each Workstation

Requests a part only if readyCompletes a partWaits for message from successor workstationWhen received, says pick&place robot to place part on the conveyor beltSend part coming message to successorSend part request message to predecessor

Receiving ws controller counts remaining number of partsShipping ws controller

Removes part from conveyor beltSend part complete message to production manager interface

For this state-dependent object: statecharts

Line W.S. Controller Statechart

Line Workstation Controller Superstate

B1: WorkstationStartup

Part ProcessingSuperstate

Part RequestingSuperstate

Part Requesting

Part Processing

Part ProcessingSuperstate Part not

Requested

Part has beenRequested

B1: WorkstationStartup

B15: Part Coming C2: Part Request

Line W.S. Controller Statechart

Awaiting PartFrom

Predecessor WS

RobotPicking

AssemblingPart

Awaiting Part Request fromSuccessor WS

PartArriving

RobotPlacing

B1:WS startup /B2: Part Request

B3:Part Coming/B4: Next Operation

Request

Part Processing Superstate

B8:Part Arrived/B9: Robot

Pick

B10:Part Ready/B11: Start Assembly

B14:Part Placed/B15: Part ComingB15a: Part Request

B12: Operation End[Part Has Been Requested] /

B13: Robot Place

B12: Operation End[Part Not Requested]

C2: Part Request /B13: Robot Place

Dynamic ModelIdea: we refine use cases using collaboration

diagramsFactory operator has client/server use cases

Client: OperatorInterfaceServer: AlarmHandlingServer, WSStatusServer

Process Engineer has client/server use casesClient: ProcessEngineerInterfaceServer: ProcessPlanServer, OperationServer

Production Manager has:client/server use case: Create/Modify Work Order

Client: ProductionManagerInterfaceServer: ProcessPlanServer, WorkOrderServer

distributed control use case: Manufacture Part

S1.1: AlarmRequest

Collab. Diagrams: View Alarms, View WS Status

<<user interface>>: OperatorInterface

<<entity>>: AlarmHandlingServer

<<actor>>

: FactoryOperator

S1: OperatorRequest


<<entity>>: WorkstationStatusServer

<<actor>>

: FactoryOperator

S1.3: DisplayInfo S1.2: Alarm

Data

V1: OperatorRequest

V1.3: DisplayInfo V1.1: WS

Status RequestV1.2: Workstation

Data

Use Cases

Collab. Diagrams: Generate Alarm and Notify

M1: WorkstationInput

<<external system>>: Robot

<<state dependent control>>: WorkstationController

<<actor>>

: FactoryOperator

M4: DisplayInfo

<<entity>>: AlarmHandlingServer


M2: Alarm

M3: AlarmMulticast

Use Cases

Collab. Diagrams: Generate WS Status and Notify

N1: WorkstationInput

<<external system>>: Robot

<<state dependent control>>

: WorkstationController

<<actor>>

: FactoryOperator

N4: DisplayInfo

<<entity>>: WorkstationStatusServer


N2: WorkstationData

N3: WorkstationStatus Multicast

Use Cases

Collab. Diagrams: Create/Update Operation,

Create/Update Process Plan

<<user interface>>: ProcessEngineerInterface

<<entity>>: ProcessPlanServer

<<actor>>

: ProcessEngineer

O1: Operation Input,P2: Process Plan Input

<<entity>>: OperationServer

P2.2: OperationRequest

P2.3: OperationInfo

O1.3: Operation Info,P2.5: Process Plan Info

P2.1: CreateProcess Plan

P2.4: ProcessPlan Info

O1.1: CreateOperation

O1.2: OperationInfo

Use Cases

Collab. Diagrams: Create/Modify Work Order

<<user interface>>: ProcessEngineerInterface


<<actor>>

: ProductionManager

R1, R2: Production Input

<<entity>>: WorkOrderServer

R2.2: Create R2.3: PartInfo

R1.3, R2.5: Production Info

R1.1: Process Plan Request

R1.2: ProcessPlan Info

R2.1: Create

R2.4: WorkOrder Info

<<entity>>: PartServer

Use Cases

Collaboration Diagrms: Receive Part

<<user interface>>: ProductionManager

Interface

<<external system>>: Pick&PlaceRobot

<<state dependent ctrl>>firstLineWSController

<<state dependent ctrl>>: ReceivingWS

Controller

<<actor>>

: ProductionManager

A1: ProductionInput

A5 = B3: PartComing

A3: Pick & PlaceRobot Command

A4: Pick & PlaceRobot Status

A2: Start Part

B2: Part Request

Use Cases

Note: it isn’t an UML notation

Collaboration Diagrams: Process Part at WS

<<external system>>: AssemblyRobot

<<state dependent ctrl>>successorLine

WorkStationController

<<state dependent ctrl>>aLineWorkStation

Controller

C2, C15a: PartRequest

B11: StartAssembly

B2, B15a: Part Request


<<entity>>: OperationServer

<<state dependent ctrl>>predecessorLine

WorkStationController


A15=B3: Part Coming

B15=C3: Part Coming

B5: OperationRequest

B6: OperationInfo

B12: OperationEnd

B4: Next OperationRequest

B7: OperationInfo

B9: Robot Pick, B13: Robot Place

B8: Part Arrived,B10: Part Ready, B14: Part Placed

Collaboration Diagrams: Ship Part

<<user interface>>: ProductionManager

Interface

<<state dependent ctrl>>: ShippingWorkStation

Controller

C2: Part Request<<state dependent ctrl>>

lastLineWorkStationController B15=C3: Part

Coming


<<actor>>

: ProductionManager

C7: Part Complete

C5: Pick & PlaceRobot Command

C4: Part Arrived

C6: Pick & PlaceRobot Status

C8: Production Info

Use Cases

Subsystem StructuringIdea: we structure the system in subsystems and then develop the

subsystem collaboration diagramsTwo things to considerate:

Geographical distribution (e.g. client/server)Use-case-based collaboration diagrams

From View alarms: alarm handler server, operator interfaceFrom View ws status: ws status serverFrom Create/update operation/process plan: process engineer interface, operation server and process plan server

Two servers used together process planning serverProcess planning server + process engineer interface process planning subsystem

From Create/modify work order: production manager interface, part server, work order server

Two servers production management serverFrom Manufacture part: Receiving/Line/Shipping Workstation controller, ws status server

All in a part processing subsystem

Factory Automation System

<<actor>>

: ProductionManager

<<actor>>

: ProcessEngineer

<<aggregatesubsystem>>

: ProcessPlanning

<<actor>>

: Operator

Start Part

<<serversubsystem>>

: AlarmHandlingServer

<<aggregatesubsystem>>: ProductionManagement


: PartProcessing


<<externalsystem>>

: Pick&PlaceRobot

<<externalsystem>>

: AssemblyRobot

<<system>>: FactoryAutomationSystem

ProcessPlan Input

ProcessPlan Info Process

Plan Info

ProcessPlan Request

Production Input

Production Info

Operation Info

Display Info

AlarmAlarm

Request

AlarmData

Part Complete

WSRequest

WSData

OperatorRequest

AssemblyRobot Command Assembly

Robot StatusPick & Place

Robot Command

Pick & PlaceRobot Status

NextOperationRequest

Tasks

Process Planning Subsystem

: ProcessEngineer

OperationRequest

<<aggregate subsystem>>: ProcessPlanning

ProcessPlan Input

ProcessPlan Info

ProcessPlan Info

CreateProcess Plan

Operation Info



: PartProcessing


Operation Info

ProcessPlan Request

ProcessPlan Info

CreateOperation

Operation Info

<<server subsystem>>: ProcessPlanningServer

<<actor>>

<<user interface>>: ProcessEngineer

Interface

Tasks

<<entity>>: ProcessPlan

Server

<<entity>>: Operation

Server

Production Management Subsystem

<<actor>>Start Part


: PartProcessing

Production Input

Production Info

Part Complete

<<aggregate subsystem>> : ProductionManagement

<<user interface>>: Production

ManagerInterface

<<entity>>: WorkOrder

Server


<<serversubsystem>>

: ProcessPlanningServer

Process Plan Request

Process Plan Info

: ProductionManager

Create

Create

Work OrderInfo

PartInfo

<<server subsystem>>: ProductionManagementServer

Tasks

Part Processing Subsystem

<<serversubsystem>>



: ProcessPlanning


<<ctrl subsystem>>: ReceivingWorkstationController

<<ctrl subsystem>>: Shipping

WorkstationController

<<ctrl subsystem>>: Line Workstation

Controller

<<serversubsystem>>: WorkstationStatusServer


<<externalsystem>>

: AssemblyRobot

<<externalsystem>>

: Pick&PlaceRobot

<<externalsystem>>

: Pick&PlaceRobot

<<externalsystem>>

: Pick&PlaceRobot

Alarm

Alarm

Alarm

WSRequest

WSData

StartPart

PartComing

PartRequest

PartComing

PartComplete

PartRequest

Pick & PlaceRobot

CommandPick & Place

Robot Command

Pick & PlaceRobot

Command

Operation Info





AssemblyRobot

CommandAssembly

Robot Status

WSStatus

Tasks<<aggregate subsystem>>

: PartProcessing

Static Model of Composite Classes

<<serversubsystem>>

AlarmHandlingServer

<<user interface>>OperatorInterface

<<serversubsystem>>Workstation

Status Server

<<controlsubsystem>>

Line WSController

<<controlsubsystem>>Shipping WS

Controller

<<controlsubsystem>>Receiving WS

Controller

<<user interface>>ProductionManagerInterface

<<serversubsystem>>

Process PlanningServer

<<user interface>>Process

EngineerInterface

<<serversubsystem>>Production

ManagementServer

Is Client of 1

11

1

1

11

1

1

1

1

1

11

1

1

1

1..*

1..*1

1 1

1

1..*

1

1..*

11

1

Is Client of

Is Client of Is Client of

Is Client of

Is Client of

Starts Part at Sends Part to Sends Part to

Sends Part to

Sends WSstatus to

Sends Alarm to

Sends Alarm to

Sends Alarm to

Sends Message

to

Conceptual model

Distributed Software Architecture

Idea: each component of a distributed architecture executes on its own physical node and communicates with other components with messages. Steps:

1. Splitting system in separate nodes; can operate separatelyEach ws controller: each one can operate if others are unavailable (sensors and actuators associated to them)Process planning server, production management s., alarm handling s.: if separated can respond quickly to requestsWs status server; two possibilities:

One server for the whole systemOne per ws The second one is better for two reasons:

High message traffic between this server and corresponding line ws controllerEach ws node can supply both controller and server

Interfaces subsystems: production manager (1), process engineer (1 each), operator(1 each)

Distributed Software Architecture

2. Design precise message communicationSynchronous msg for client/server communicationLoosely coupled msg for alarms, …For greatest flexibility, loosely coupled msg for communication between various ws controller components, production manager interface, robots and alarm handling server

3. Multiple-client/multiple-server communicationOperator interface – ws status server:

Status displayed not only when requested, but on changeCan receive data from differents workstations concurrently

alarmRequest

(in request, out alarmData)

Factory Automation System: Subsystem Interfaces

<<actor>>

: ProductionManager

<<actor>>

: ProcessEngineer


: ProcessPlanning

<<actor>>

: Operator

startPart(partInfo)

<<serversubsystem>>




: PartProcessing


<<externalsystem>>

: Pick&PlaceRobot

<<externalsystem>>

: AssemblyRobot

<<system>>: FactoryAutomationSystem

ProcessPlan Input

ProcessPlan Info processPlan

Request (in request, out processPlan

Info)

Production Input

Production Info

Display Info

alarm(alarmData)

alarmNotification(alarmData)

part Complete(partInfo)

WS_Request(in request,out wsData)

WSNotification

(wsData)

OperatorRequest

assemblyRobotCommand assembly

RobotStatuspick&place

Robot Command

pick&placeRobot Status

nextOperation

Request (inrequest, out

operationInfo)

Back

createProcess PlanRequest (in

request, outprocessPlanInfo)

Process Planning Subsystem: Subs. Interfaces

: ProcessEngineer

<<entity>>: ProcessPlan

Server

<<entity>>: Operation

Server

<<aggregate subsystem>>: ProcessPlanning

ProcessPlan Input

ProcessPlan Info



: PartProcessing

<<server subsystem>>: ProcessPlanningServer

<<actor>><<user interface>>: ProcessEngineer

Interface

createOperationRequest (in request, out operationInfo)

operationRequest (in request, out operationInfo)

processPlanRequest (in request, out processPlanInfo)

nextOperationRequest (in request, out operationInfo)

Back

workOrderRequest(in request, outworkOrderInfo)

Production Management Subsystem: S. Interfaces

<<actor>> startPart(partInfo)


: PartProcessing

Production Input

Production Info

partComplete(partInfo)

<<aggregate subsystem>> : ProductionManagement

<<user interface>>: Production

ManagerInterface

<<entity>>: WorkOrder

Server


<<serversubsystem>>


processPlanRequest(in request, out

processPlanInfo)

: ProductionManager

partInfoRequest(in request, out

partInfo)

<<server subsystem>>: ProductionManagementServer

Back

wsStatus(status)

Part Processing Subsystem:Subsystem Interfaces

<<serversubsystem>>



: ProcessPlanning


<<ctrl subsystem>>: ReceivingWorkstationController

<<ctrl subsystem>>: Shipping

WorkstationController

<<ctrl subsystem>>: Line Workstation

Controller

<<serversubsystem>>: WorkstationStatusServer


<<externalsystem>>

: AssemblyRobot

<<externalsystem>>

: Pick&PlaceRobot

<<externalsystem>>

: Pick&PlaceRobot

<<externalsystem>>

: Pick&PlaceRobot

alarm(alarmData)

wsNotification

(wsData)

wsRequest(in request, out wsData)

startPart(partInfo)

partComing

(partInfo)

partRequest

(partInfo)

pick&PlaceRobot

Command

pick&PlaceRobot

Command

nextOperationRequest

(in request, out operationInfo)

pick&PlaceRobot Status

pick&PlaceRobotStatus

assemblyRobot Status

alarm(alarmData)

alarm(alarmData)

partComing

(partInfo)

partRequest

(partInfo)

partComplete(partInfo)

pick&PlaceRobot

Commandpick&PlaceRobotStatus

assemblyRobot

Command

Back<<aggregate subsystem>>

: PartProcessing

System ConfigurationTo configure individual target systems we may

Define different workastationsDefine parameters such as wsID, alarm name, … for parameterized componentsConnect component instance and allocate them to phisical nodes

There are different target configurationsHighly distributed: see next slide

Localized autonomyAdequate performanceFailure of a node not impacting on another immediately

Grouping process planning server, production management s., alarm handling serverAs above + Process engineer interface + production manager interface in a single node

Multiuser interactive node

System Configuration: ProcessEngineer

Interface{1 per Engineer}

: ProdutionManagerInterface

{1 node}

<<Internet>>

: Receiving WSController{1 node}

<<factory LAN>>: AlarmHandling

Server{1 node}

: OperatorInterface

{1 per operator}

: Line WSNode

{1 node}

: Shipping WSController{1 node}


{1 node}

: ProductionMa-nagementServer

{1 node}

comet, a case study distributed factory automation system software engineering 2000-2001 petta...

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