The Currency Control System is a S/W program that interacts with currency control equipment to store and exchange various international currencies. The Currency Control System responds to the following commands:

- Set Available Currency Funds, e.g. DM funds = 1000,

- Get Available Currency Funds, e.g. DM funds = 1000,

- Set a Currency Exchange Rate, e.g. US -> DM = 1.50,

- Get a Currency Exchange Rate, e.g. US -> DM = 1.50.

- Exchange a Currency, e.g. 10 US -> 15DM.

The Currency Control System responds to these commands with the following responses:

- Display Status, e.g. DM funds = 1000,

- Dispense an Amount of a Currency, e.g. DM = 15.

The following information (data) is passed between the HW Equipment and the Currency Control System:

- an in currency type, e.g. US, DM, FR,

- an in currency amount, e.g. 100,

- an out currency type, e.g. US, DM, FR,

- an out currency amount, e.g. 150,

- a currency exchange rate, e.g. 1.5.

A currency exchange rate is a float that is used to convert an amount of an input currency to compute the amount of an output currency, e.g. the currency exchange rate of a US dollar to a Deutschemark is 1.5. A in currency amount or out currency amount is an integer. It is an input amount that a user inputs and an output amount that a user receives during an exchange. An in currency type or out curreny type is an available international currency, e.g. US, DM, and FR.

System Name	Attribute Names	System Operation Names
CurrencyControlSystem	availCurrency currencyRates inCurrencyType outCurrencyType inCurrencyAmount outCurrencyAmount	getAvailCurrency setAvailCurrency getCurrencyRate setCurrencyRate exchangeCurrency
HWEquipment		dispenseCurrency displayStatus

System Name: Currency Control System

System Access: Public

System Imports: NA

Enclosing System: NA

System Description: The Currency Control System controls the exchange of currencies.

Entity Name	Type of Entity	Enclosing System
CurrencyControlSystem	System	--
availCurrency	Attribute	CurrencyControlSystem
currencyRates	Attribute	CurrencyControlSystem
inCurrencyType	Attribute	CurrencyControlSystem
outCurrencyType	Attribute	CurrencyControlSystem
inCurrencyAmount	Attribute	CurrencyControlSystem
outCurrencyAmount	Attribute	CurrencyControlSystem
getAvailCurrency	System Operation	CurrencyControlSystem
setAvailCurrency	System Operation	CurrencyControlSystem
getCurrencyRate	System Operation	CurrencyControlSystem
setCurrencyRate	System Operation	CurrencyControlSystem
exchangeCurrency	System Operation	CurrencyControlSystem
HWEquipment	System	--
dispenseCurrency	System Operation	HWEquipment
displayStatus	System Operation	HWEquipment

System Use Cases/Sub-use Cases Table

Number	Initiating Actor	Use Case/Subuse Case	Use Case Description
1	Maintainer	Maintain Currency System	General use case with sub-use cases
1.1	Maintainer	Set Available Currency	Input Event - setAvailableCurrency, Output Event - displayStatus
1.2	Maintainer	Get Available Currency	Input Event - getAvailableCurrency, Output Event - displayStatus
1.3	Maintainer	Set Currency Rate	Input Event - setAvailableCurrency, Output Event - displayStatus
2	User	Use Currency System	General use with sub-use cases
2.1	User	Get Currency Rate	Input Event - getCurrencyRate, Output Event - displayStatus
2.2	User	Exchange Currency	Input Event - exchangeCurrency, Output Event - dispenseCurrency

Use Case Table - Maintain Currency System Use Case

Sequence Number	Sender System	Receiver System	Invoked Operation	Description
1	HW Equipment	Currency Control System	setAvailableCurrency	Input Event
2	Currency Control System	HW Equipment	displayStatus	Output Event
3	HW Equipment	Currency Control System	getAvailableCurrency	Input Event
4	Currency Control System	HW Equipment	displayStatus	Output Event
5	HW Equipment	Currency Control System	setCurrencyRate	Input Event
6	Currency Control System	HW Equipment	displayStatus	Output Event

Use Case Table - Use Currency System Use Case

Sequence Number	Sender System	Receiver System	Invoked Operation	Description
1	HW Equipment	Currency Control System	getCurrencyRate	Input Event
2	Currency Control System	HW Equipment	displayStatus	Output Event
3	HW Equipment	Currency Control System	exchangeCurrency	Input Event
4	Currency Control System	HW Equipment	displayStatus	Output Event
5	Currency Control System	HW Equipment	dispenseCurrency	Output Event

Creams () Returns number of creams

The basic transformation is the exchangeCurrency system operation that computes an Out Currency Amount based upon an In Currency Amount, In Currency Type, and Out Currency Type. The basic transformation is:

Out Currency Amount = In Currency Amount * currencyRates [In Currency Type]

Correctness assertions must be identified to ensure that correct outAmount's are computed.

System Operation Name	Input Parameters	Transformation	Return Type
getAvailCurrency	OutCurrencyType		int
setAvailCurrency	OutCurrencyType OutCurrencyAmount	Update outCurrencyAmount	void
getCurrencyRate	OutCurrencyType InCurrencyType		float
setCurrencyRate	OutCurrencyType InCurrencyType CurrencyRate	Update currencyRates
exchangeCurrency	InCurrencyType InCurrencyAmount OutCurrencyType	outCurrencyAmount = currencyRates [inCurrencyType] * inCurrencyAmount	int

Class Name	Attribute Names	Relationship Traversal Path Names	Operation Names
Currency	availCurrency currencyRates		setAvailCurrency getAvailCurrency getCurrencyRate setCurrencyRate exchangeCurrency
USCurrency			exchangeCurrency
DMCurrency			exchangeCurrency
CurrencyController		aDM aUS	setAvailCurrency getCurrencyRate setCurrencyRate exchangeCurrency getAvailCurrency
HWInterface		aCurrencyController	dispenseCurrency setAvailCurrency getCurrencyRate setCurrencyRate exchangeCurrency getAvailCurrency

Data Dictionary for Object Model - Currency Control System

Entity Name	Type of Entity	Enclosing Class
Currency	Class	--
availCurrency	Attribute	Currency
currencyRates	Attribute	Currency
setAvailCurrency	Operation	Currency
getAvailCurrency	Operation	Currency
getCurrencyRate	Operation	Currency
setCurrencyRate	Operation	Currency
exchangeCurrency	Operation	Currency
USCurrency	Class	--
exchangeCurrency	Operation	USCurrency
DMCurrency	Class	--
exchangeCurrency	Operation	DMCurrency
CurrencyController	Class	--
setAvailCurrency	Operation	CurrencyController
getCurrencyRate	Operation	CurrencyController
setCurrencyRate	Operation	CurrencyController
exchangeCurrency	Operation	CurrencyController
getAvailCurrency	Operation	CurrencyController
aDM	Traversal Path for 1:1 Aggregation	CurrencyController
aUS	Traversal Path for 1:1 Aggregation	CurrencyController
HWInterface	Class	--
dispenseCurrency	Operation	HWInterface
setAvailCurrency	Operation	HWInterface
getCurrencyRate	Operation	HWInterface
setCurrencyRate	Operation	HWInterface
exchangeCurrency	Operation	HWInterface
getAvailCurrency	Operation	HWInterface
aCurrencyController	Traversal Path for 1:1 Aggregation	HWInterface

Sequence #	Sender System/Object	Receiver System /Object	Invoked Operation	Description
1	HWEquipment	aHWInterface	getAvailableCurrency	Input Event
2	aHWInterface	aCurrencyController	getAvailableCurrency	Message
3	aCurrencyController	aCurrency	getAvailableCurrency	Message
4	aHWInterface	HWInterface	displayStatus	Output Event
5	HWEquipment	aHWInterface	setAvailableCurrency	Input Event
6	aHWInterface	aCurrencyController	setAvailableCurrency	Message
7	aCurrencyController	aCurrency	setAvailableCurrency	Message
8	aHWInterface	HWInterface	displayStatus	Output Event
9	HWEquipment	aHWInterface	setCurrencyRate	Input Event
10	aHWInterface	aCurrencyController	setCurrencyRate	Message
11	aCurrencyController	aCurrency	setCurrencyRate	Message
12	aHWInterface	HWInterface	displayStatus	Output Event

Sequence #	Sender System/Object	Receiver System /Object	Invoked Operation	Description
1	HWEquipment	aHWInterface	getCurrencyRate	Input Event
2	aHWInterface	aCurrencyController	getCurrencyRate	Message
3	aCurrencyController	aCurrency	getCurrencyRate	Message
4	aHWInterface	HWInterface	displayStatus	Output Event
5	HWEquipment	aHWInterface	exchangeCurrency	Input Event
6	aHWInterface	aCurrencyController	exchangeCurrency	Message
7	aCurrencyController	aCurrency	exchangeCurrency	Message
8	aHWInterface	HWInterface	displayStatus	Output Event
9	aHWInterface	HWInterface	dispenseCurrency	Output Event

The basic transformation is the exchangeCurrency operation

void int exchangeCurrency (Currency anInCurr, int anInCurrAmt)

transformation: int anOutAmount = anInCurrAmt * currencyRates [anInCurr]

Correctness assertions must be identified to ensure that correct outAmount's are computed.

Class Name	Operation Name	Input Parameters	Transformation	Return Type
Currency	setAvailCurrency	int amount	availCurrency = amount	void
Currency	getAvailCurrency			int
Currency	getCurrencyRate	Currencies anInCurr		float
Currency	setCurrencyRate	Currencies anInCurr float aRate	currencyRates [anInCurr] = aRate	void
Currency	exchangeCurrency	Currencies anInCurr int anInCurrAmt		int
USCurrency	exchangeCurrency	Currencies anInCurr int anInCurrAmt	int anOutAmount = anInCurrAmt * currencyRates [anInCurr]	int
DMCurrency	exchangeCurrency	Currencies anInCurr int anInCurrAmt	int anOutAmount = anInCurrAmt * currencyRates [anInCurr]	int
CurrencyController	setAvailCurrency	Currency* aCurrency int amount		void
CurrencyController	getCurrencyRate	Currency* aCurrency Currencies anInCurr		float
CurrencyController	setCurrencyRate	Currency* aCurrency Currencies anInCurr float aRate
CurrencyController	exchangeCurrency	Currency* aCurrency Currencies anInCurr int anInCurrAmt
CurrencyController	getAvailCurrency	Currency* aCurrency		int
HWInterface	dispenseCurrency	int anOutAmt		void
HWInterface	setAvailCurrency	Currencies anOutCurr int amount		void
HWInterface	getCurrencyRate	Currencies anInCurr Currencies anOutCurr		void
HWInterface	setCurrencyRate	Currencies anInCurr Currencies anOutCurr float aRate
HWInterface	exchangeCurrency	Currencies anInCurr Currencies anOutCurr int anInCurrAmt
HWInterface	getAvailCurrency	Currencies anOutCurr		void

7 - System/Subsystems for the H/W and S/W Configuration

Element	Prototype	Production Implementation
Processors	Single Processor Intel Processor	Single Processor Intel Processor
Devices	Display	HW Equipment
Operating System	MS-DOS	MS-DOS
Graphic User Interface	Text Only	Text Only
Language	C++	C++
Libraries	N/A	N/A
Components/DLLs/EXEs	CURRENCY.EXE	CURRENCY.EXE
Processes/Threads/Tasks	N/A	N/A
Persistent Data Storage	C++ Streams	TBD
Distribution and Connectivity	N/A	N/A
Test Cases	5	5
Help/User/Installation Documentation	N/A	Yes

The Processor - Processes Diagram displays the processor and concurrent processes in the system as boxes. In the Currency Control System there is only one processor with a single process. There is no concurrency.

//Currency Control System C++ Prototype

//Condensed single file C++ prototype for educational purposes

#include <iostream.h>

enum Currencies { US, DM, FR }; //Global Type Declaration

///////////////////////////////////////////////////////////////

class Currency { //Base Class

protected:

int availCurrency;

float currencyRates [2];

public:

void setAvailCurrency (int amount){availCurrency = amount; }

int getAvailCurrency () {return availCurrency; }

float getCurrencyRate (Currencies anInCurr)

{ return currencyRates [anInCurr]; }

void setCurrencyRate (Currencies anInCurr, float aRate)

{currencyRates [anInCurr] = aRate; }

virtual int exchangeCurrency (Currencies anInCurr, int anInCurrAmt) = 0;

};

////////////////////////////////////////////////////////////////

class USCurrency : public Currency {//Derived Class - Details to

public: // be added

int exchangeCurrency (Currencies anInCurr, int anInCurrAmt)

{ int anOutAmount = anInCurrAmt * currencyRates [anInCurr];

return anOutAmount;}

};

////////////////////////////////////////////////////////////////

class DMCurrency : public Currency { //Derived Class - Details to

public: // be added

int exchangeCurrency (Currencies anInCurr, int anInCurrAmt)

{ int anOutAmount = anInCurrAmt * currencyRates [anInCurr];

return anOutAmount;}

};

///////////////////////////////////////////////////////////////

class CurrencyController {

public:

DMCurrency aDM;

USCurrency aUS;

void setAvailCurrency (Currency *aCurrency, int amount)

{ aCurrency -> setAvailCurrency (amount); }

float getCurrencyRate (Currency *aCurrency, Currencies anInCurr)

{ float aRate = aCurrency -> getCurrencyRate (anInCurr);

return aRate;}

void setCurrencyRate (Currency *aCurrency, Currencies anInCurr, float aRate)

{ aCurrency -> setCurrencyRate (anInCurr, aRate); }

int exchangeCurrency (Currency *aCurrency, Currencies anInCurr, int anInCurrAmt)

{ int anOutAmount;

anOutAmount = aCurrency -> exchangeCurrency (anInCurr, anInCurrAmt);

return anOutAmount; }

int getAvailCurrency (Currency *aCurrency)

{int anAmount = aCurrency -> getAvailCurrency ();

return anAmount; }

};

///////////////////////////////////////////////////////////////

class HWInterface {

CurrencyController aCurrencyController;

public:

//void displayStatus (String aString) { } //Calls to cout <<

//simulate calls to displayStatus

void dispenseCurrency (int anOutAmt)

{cout << "The dispensed amount is " << anOutAmt << ".\n"; }

void setAvailCurrency (Currencies anOutCurr, int amount)

{if (anOutCurr == DM) aCurrencyController.setAvailCurrency (&aCurrencyController.aDM, amount); }

void getCurrencyRate (Currencies anInCurr, Currencies anOutCurr)

{ float aRate = 0.0;

if (anOutCurr == DM)

{ aRate = aCurrencyController.getCurrencyRate (&aCurrencyController.aDM, anInCurr);

cout << "The current rate is " << aRate << ".\n";}

}

void setCurrencyRate (Currencies anInCurr, Currencies anOutCurr, float aRate)

{ if (anOutCurr == DM)

{ aCurrencyController.setCurrencyRate (&aCurrencyController.aDM, anInCurr, aRate);

cout << "The current rate has been set to " << aRate << ".\n";}

}

void exchangeCurrency (Currencies anInCurr, Currencies anOutCurr, int anInCurrAmt)

{ int anOutAmount;

if (anOutCurr == DM) {

anOutAmount = aCurrencyController.exchangeCurrency (&aCurrencyController.aDM, anInCurr, anInCurrAmt);

dispenseCurrency (anOutAmount);}

}

void getAvailCurrency (Currencies anOutCurr)

{ int anAmount = 0;

if (anOutCurr == DM)

{ anAmount = aCurrencyController.getAvailCurrency (&aCurrencyController.aDM);

cout << "Current available currency is " << anAmount << ".\n"; }

}

};

///////////////////////////////////////////////////////////////

int main () //Test Case

{ HWInterface aHWInterface;

cout << "Setting the available currency for DM - Deutschemarks.\n";

aHWInterface.setAvailCurrency (DM, 1000);

aHWInterface.getAvailCurrency (DM);

cout << "Setting the current exchange rate for DM - Deutschemarks.\n";

aHWInterface.setCurrencyRate (US, DM, 1.5);

aHWInterface.getCurrencyRate (US, DM);

cout << "Exchanging 1 US dollar for Deutschemarks.\n";

aHWInterface.exchangeCurrency (US, DM, 1);

return 0; }

///////////////////////////////////////////////////////////////

//Sample Output

//Setting the available currency for DM - Deutschemarks.

//The available currency is 1000.

//Setting the current exchange rate for DM - Deutschemarks.

//The current rate has been set to 1.5.

//The current rate is 1.5.

//Exchanging 1 US dollar for Deutschemarks.

//The dispensed amount is 1.