The Cruise Control Control System shall maintain a desired speed when engaged.  It shall receive control commands (on, set, compare, resume, brake, and off) from cruise control HW (Timer, Driver Buttons, and Brake Sensor).  It shall get the current speed from cruise control HW (Speedometer).  It shall send a throttle setting (released, increasing, no_change, decreasing) to cruise control HW (Throttle).

System Name	Attribute Names	System Operation Names
CruiseControlHW		getSpeed setThrottle releaseThrottle
CruiseControlSystem	currentSpeed desiredSpeed throttleSetting	on setDesiredSpeed compare brake resume off

System Name: Cruise Control System

System Access: Public

System Imports: NA

Enclosing System: NA

System Description: The Cruise Control System controls an automotive throttle.

Entity Name	Type of Entity	Enclosing System
CruiseControlSystem	System	--
CruiseControlHW	Interacting System	--
currentSpeed	System Attribute	CruiseControlSystem
desiredSpeed	System Attribute	CruiseControlSystem
throttleSetting	System Attribute	CruiseControlSystem
getSpeed	System Operation	CruiseControlHW
setThrottle	System Operation	CruiseControlHW
releaseThrottle	System Operation	CruiseControlHW
on	System Operation	CruiseControlSystem
setDesiredSpeed	System Operation	CruiseControlSystem
compare	System Operation	CruiseControlSystem
brake	System Operation	CruiseControlSystem
resume	System Operation	CruiseControlSystem
off	System Operation	CruiseControlSystem

Number	Initiating Actor	Use Case/Subuse Case	Use Case Description
1	User	Operate Cruise Control	This use case has 6 sub-use cases
1.1	User	Turn Cruise Control On	Input Event on
1.2	User	Set Desired Speed	Input Event setDesiredSpeed - Output Event getSpeed
1.3	User	Compare Desired and Current Speed	Input Event compare - Output Events getSpeed setThrottle
1.4	User	Brake and Release Cruise Control	Input Event brake Output Event releaseThrottle
1.5	User	Resume Cruise Control	Input Event resume
1.6	User	Turn Cruise Control Off	Input Event off Output Event releaseThrottle

Sequence Number	Sender System	Receiver System	Invoked Operation	Description
1	Cruise Control HW	Cruise Control System	on	Input Event
2	Cruise Control HW	Cruise Control System	setDesiredSpeed	Input Event
3	Cruise Control System	Cruise Control HW	getSpeed	Output Event
4	Cruise Control HW	Cruise Control System	compare	Input Event
5	Cruise Control System	Cruise Control HW	getSpeed	Output Event
6	Cruise Control System	Cruise Control HW	setThrottle	Output Event
7	Cruise Control HW	Cruise Control System	brake	Input Event
8	Cruise Control System	Cruise Control HW	releaseThrottle	Output Event
9	Cruise Control HW	Cruise Control System	resume	Input Event
10	Cruise Control HW	Cruise Control System	off	Input Event
11	Cruise Control System	Cruise Control HW	releaseThrottle	Output Event

State Name	Event Name	Transition Condition	Transition Action	Transition Next State
OffState	on()			ReadyState
OffState	off()			TerminalState
ReadyState	setDesiredSpeed()		getSpeed	ControllingState
ReadyState	off()		releaseThrottle	TerminalState
ControllingState	off()		releaseThrottle	TerminalState
ControllingState	compare()		getSpeed setThrottle	ControllingState
ControllingState	brake()		releaseThrottle	SuspendedState
SuspendedState	resume()			ControllingState
SuspendedState	off()		releaseThrottle	TerminalState

Creams (return aNumber) Returns number of creams

System Name	System Operation Name	Input Parameters	Transformation	Return Type
CruiseControlSystem	on			void
CruiseControlSystem	setDesiredSpeed		desiredSpeed = currentSpeed	void
CruiseControlSystem	compare		if (currentSpeed < desiredSpeed) throttleSetting = increasing; if (currentSpeed == desiredSpeed) throttleSetting = no_change; if (currentSpeed > desiredSpeed) throttleSetting = decreasing;	void
CruiseControlSystem	brake		throttleSetting = released	void
CruiseControlSystem	resume			void
CruiseControlSystem	off		throttleSetting = released	void

Class Name	Attribute Names	Relationship Traversal Path Names	Operation Names
HWInterfaceResponses			getSpeed setThrottle releaseThrottle
Throttle	setting		getThrottleSetting
Speed	desiredSpeed currentSpeed speedComparison		setCurrentSpeed setDesiredSpeed currentSpeedComparison
CruiseControl	state	theHWInterface theThrottle theSpeed	on setDesiredSpeed compare brake resume off
HWInterfaceEvents		theCruiseControl	on setDesiredSpeed compare brake resume off

Entity Name	Type of Entity	Enclosing Class
HWInterfaceResponses	Class	--
Throttle	Class	--
Speed	Class	--
CruiseControl	Class	--
HWInterfaceEvents	Class	--
setting	Attribute	Throttle
desiredSpeed	Attribute	Speed
currentSpeed	Attribute	Speed
speedComparison	Attribute	Speed
state	Attribute	CruiseControl
getSpeed	Operation	HWInterfaceResponses
setThrottle	Operation	HWInterfaceResponses
releaseThrottle	Operation	HWInterfaceResponses
getThrottleSetting	Operation	Throttle
setCurrentSpeed	Operation	Speed
setDesiredSpeed	Operation	Speed
currentSpeedComparison	Operation	Speed
on	Operation	CruiseControl
setDesiredSpeed	Operation	CruiseControl
compare	Operation	CruiseControl
brake	Operation	CruiseControl
resume	Operation	CruiseControl
off	Operation	CruiseControl
on	Operation	HWInterfaceEvents
setDesiredSpeed	Operation	HWInterfaceEvents
compare	Operation	HWInterfaceEvents
brake	Operation	HWInterfaceEvents
resume	Operation	HWInterfaceEvents
off	Operation	HWInterfaceEvents
theHWInterface	Traversal Path for 1:1 Aggregation	CruiseControl
theThrottle	Traversal Path for 1:1 Aggregation	CruiseControl
theSpeed	Traversal Path for 1:1 Aggregation	CruiseControl
theCruiseControl	Traversal Path for 1:1 Aggregation	HWInterfaceEvents

Sequence #	Sender System/Object	Receiver System/Object	Invoked Operation	Description
0	Cruise Control HW	theHWInterfaceEvents	on	Input Event
1	theHWInterfaceEvents	theCruiseControl	on	Message
2	Cruise Control HW	theHWInterfaceEvents	setDesiredSpeed	Input Event
3	theHWInterfaceEvents	theCruiseControl	setDesiredSpeed	Message
4	theCruiseControl	theHWInterfaceResponse	getSpeed	Message
5	theHWInterfaceResponse	Cruise Control HW	getSpeed	Output Event
6	theCruiseControl	theSpeed	setDesiredSpeed	Message
7	Cruise Control HW	theHWInterfaceEvents	compare	Input Event
8	theHWInterfaceEvents	theCruiseControl	compare	Message
9	theCruiseControl	theHWInterfaceResponse	getSpeed	Message
10	theHWInterfaceResponse	Cruise Control HW	getSpeed	Output Event
11	theCruiseControl	theSpeed	setDesiredSpeed	Message
12	theCruiseControl	theSpeed	getSpeedComparison	Message
13	theCruiseControl	theThrottle	getThrottleSetting	Message
14	theCruiseControl	theHWInterfaceResponse	setThrottle	Message
15	theHWInterfaceResponse	Cruise Control HW	setThrottle	Output Event
16	Cruise Control HW	theHWInterfaceEvents	brake	Input Event
17	theHWInterfaceEvents	theCruiseControl	brake	Message
18	theCruiseControl	theHWInterfaceResponse	releaseThrottle	Message
19	theHWInterfaceResponse	Cruise Control HW	releaseThrottle	Output Event
20	Cruise Control HW	theHWInterfaceEvents	off	Input Event
21	theHWInterfaceEvents	theCruiseControl	off	Message
22	theCruiseControl	theHWInterfaceResponse	releaseThrottle	Message
23	theHWInterfaceResponse	Cruise Control HW	releaseThrottle	Output Event

State Name	Event Name	Transition Condition	Transition Action	Transition Next State
OffState	on()			ReadyState
OffState	off()			TerminalState
ReadyState	setDesiredSpeed()		theHWInterface.getSpeed theSpeed.setDesiredSpeed	ControllingState ReadyState
ControllingState	off()		theHWInterface.releaseThrottle	TerminalState
ControllingState	compare()		theHWInterface.getSpeed theSpeed.setCurrentSpeed theSpeed.currentSpeedComparison theThrottle.getThrottleSetting theHWInterface.setThrottle	ControllingState
ControllingState	brake()		theHWInterface.releaseThrottle	SuspendedState
SuspendedState	off()		theHWInterface.releaseThrottle	TerminalState
SuspendedState	resume()			ControllingState

Class Name	Operation Name	Input Parameters	Transformation	Return Type
CruiseControl	on			void
CruiseControl	setDesiredSpeed			void
CruiseControl	compare			void
CruiseControl	brake			void
CruiseControl	resume			void
CruiseControl	off			void
HWInterfaceEvents	on			void
HWInterfaceEvents	setDesiredSpeed			void
HWInterfaceEvents	compare			void
HWInterfaceEvents	brake			void
HWInterfaceEvents	resume			void
HWInterfaceEvents	off			void
HWInterfaceResponses	getSpeed			int
HWInterfaceResponses	setThrottle	ThrottleSetting setting		void
HWInterfaceResponses	releaseThrottle			void
Speed	setCurrentSpeed	int aSpeed	currentSpeed = aSpeed;	void
Speed	setDesiredSpeed	int aSpeed	desiredSpeed = aSpeed;	void
Speed	currentSpeedComparison		if (currentSpeed < desiredSpeed) speedComparison = too_slow; if (currentSpeed > desiredSpeed) speedComparison = too_fast; if (currentSpeed == desiredSpeed) speedComparison = ok;	SpeedComparison
Throttle	getThrottleSetting	SpeedComparison speed_comparison	switch (speed_comparison) { case too_slow : setting = increasing; break; case ok : setting = no_change; break; case too_fast : setting = decreasing; break; default: cout << "\nUnknown speed comparison - try again"; } return setting;	ThrottleSetting

//Cruise Control Application Prototype file cruise.cpp

//Single file C++ prototype for educational purposes

#include <stdio.h>

#include <iostream.h>

enum SpeedComparison {too_slow,ok,too_fast};

enum States {off_state,ready,controlling,suspended};

enum ThrottleSetting

{released,increasing,no_change,decreasing};

//-----------------------------------------------------------

class HWInterfaceResponses {

public:

HWInterfaceResponses () { }

int getSpeed () const ;

void setThrottle (ThrottleSetting setting);

void releaseThrottle ();

};

int HWInterfaceResponses::getSpeed () const

{ int currentSpeed; cout << "\nEnter the current speed ";

cin >> currentSpeed; return currentSpeed;}

void HWInterfaceResponses::setThrottle (ThrottleSetting setting)

{ cout << "The throttle setting is " << setting;

cout << "\n0 - released, 1 - increasing, 2 - no_change, 3 -decreasing";}

void HWInterfaceResponses::releaseThrottle ()

{ cout << "\nThe throttle is released\n";}

class Throttle {

private:

ThrottleSetting setting;

public:

Throttle();

ThrottleSetting getThrottleSetting (SpeedComparison speed_comparison);

};

Throttle::Throttle() { setting = released; }

ThrottleSetting Throttle::getThrottleSetting (SpeedComparison speed_comparison)

{ switch (speed_comparison)

{ case too_slow : setting = increasing; break;

case ok : setting = no_change; break;

case too_fast : setting = decreasing; break;

default: cout << "\nUnknown speed comparison - try again";

}

cout << "\nThrottle adjustment - current speed is " << speed_comparison;

cout << "\n0 - too slow, 1 - ok, 2 - too fast\n";

return setting;

}

//---------------------------------------------------------------

class Speed {

private:

int desiredSpeed;

int currentSpeed;

SpeedComparison speedComparison;

public:

Speed();

void setCurrentSpeed (int aSpeed);

void setDesiredSpeed(int aSpeed);

SpeedComparison currentSpeedComparison();

};

Speed::Speed()

{ desiredSpeed = 0; currentSpeed = 0; speedComparison = ok;

}

void Speed::setCurrentSpeed(int aSpeed)

{ currentSpeed = aSpeed; }

SpeedComparison Speed::currentSpeedComparison ()

{ if (currentSpeed < desiredSpeed)

speedComparison = too_slow;

if (currentSpeed > desiredSpeed)

speedComparison = too_fast;

if (currentSpeed == desiredSpeed)

speedComparison = ok;

return (speedComparison);

}

void Speed::setDesiredSpeed (int aSpeed)

{ desiredSpeed = aSpeed;

}

//---------------------------------------------------------------

class CruiseControl {

private:

HWInterfaceResponses theHWInterface;

States state;

Throttle theThrottle; //object theThrottle

Speed theSpeed; //object theSpeed

public:

CruiseControl ();

void on ();

void setDesiredSpeed ();

void compare ();

void brake ();

void resume ();

void off ();

};

CruiseControl::CruiseControl()

{ state=off_state;

}

void CruiseControl::on ()

{ cout <<"\nDriver pressed the on button";

switch (state)

{ case off_state:

state = ready; break;

default: cout <<"\nCannot respond to the command - try again";

}

}

void CruiseControl::setDesiredSpeed ()

{ cout <<"\nDriver pressed the set desired speed button";

switch (state)

{ case ready || controlling || suspended:

int aSpeed = theHWInterface.getSpeed();

theSpeed.setDesiredSpeed (aSpeed);

cout << "\nDesired Speed is " << aSpeed;

state = controlling; break;

default: cout <<"\nCannot respond to the command - try again";

}

}

void CruiseControl::compare ()

{ SpeedComparison aSpeedComparison;

cout <<"\nTimer sent compare command";

switch (state)

{case controlling:

int aSpeed = theHWInterface.getSpeed();

theSpeed.setCurrentSpeed (aSpeed);

cout << "The current speed is " << aSpeed;

aSpeedComparison = theSpeed.currentSpeedComparison();

ThrottleSetting aSetting = theThrottle.getThrottleSetting

(aSpeedComparison);

theHWInterface.setThrottle (aSetting);

state = controlling; break;

default: cout <<"\nCannot respond to the command - try again";

}

}

void CruiseControl::brake ()

{ cout <<"\nDriver pressed the brake";

switch (state)

{ case controlling:

theHWInterface.releaseThrottle();

state = suspended; break;

default: cout <<"\nCannot respond to the command - try again";

}

}

void CruiseControl::resume ()

{ cout <<"\nDriver pressed the resume button";

switch (state)

{ case suspended:

state = controlling; break;

default: cout <<"\nCannot respond to the command - try again";

}

}

void CruiseControl::off ()

{ cout <<"\nDriver pressed the off button.";

theHWInterface.releaseThrottle();

cout << "\nThe Cruise Control is OFF";

state = off_state;

}

//---------------------------------------------------------------

class HWInterfaceEvents {

CruiseControl theCruiseControl;

public:

void on ();

void setDesiredSpeed ();

void compare ();

void brake ();

void resume ();

void off ();

};

void HWInterfaceEvents::on () {theCruiseControl.on ();};

void HWInterfaceEvents::setDesiredSpeed ()

{theCruiseControl.setDesiredSpeed ();}

void HWInterfaceEvents::compare ()

{theCruiseControl.compare ();}

void HWInterfaceEvents::brake ()

{ theCruiseControl.brake ();}

void HWInterfaceEvents::resume ()

{theCruiseControl.resume ();}

void HWInterfaceEvents::off () {theCruiseControl.off ();}

//---------------------------------------------------------------------

int main ()

{ HWInterfaceEvents theHWInterfaceEvents;

theHWInterfaceEvents.on(); //an Event

theHWInterfaceEvents.setDesiredSpeed(); //an Event

theHWInterfaceEvents.compare(); //an Event

theHWInterfaceEvents.brake(); //an Event

theHWInterfaceEvents.resume (); //an Event

theHWInterfaceEvents.off(); //an Event

return 0;

}

//-----------------------Sample Output----------------------------------

/*Driver pressed the on button

Driver pressed the set desired speed button

Enter the current speed: 55

Timer sent compare command

Enter the current speed: 66

Throttle adjustment - current speed is: 2

0 - too slow, 1 - ok, 2 - too fast

The throttle setting is 3.

0 - released, 1 - increasing, 2 - no_change, 3 -decreasing

Driver pressed the brake

The throttle is released

Driver pressed the resume button

Driver pressed the off button

The throttle is released

The Cruise Control is OFF

*/