Req ID |
Requirement Text |
|
Non-Functional
Requirements
|
N1 |
Usability: A typical
user shall be able to start the cooking process within 10 seconds of
arrival upon their fourth use of the microwave oven. |
N2 |
Usability: A maximum of
15 keystrokes shall be required for a microwave oven cooking operation. |
N3 |
Reliability: The
microwave oven shall provide 99.999% availability. |
N4 |
Reliability: The
microwave oven shall provide a Mean Time Between Failure (MTBF) of
4,000 hours. |
N5 |
Reliability: The
microwave oven shall provide a Mean Time To Repair (MTTR) of 21
business days. |
N6 |
Reliability: The
microwave oven shall function properly with an input voltage of 120 VAC
+/- 10 VAC. |
N8 |
Reliability: The
time-of-day clock shall drift no more than 1 second over a period of
continuous operation of 30 days. |
N7 |
Performance: The timer
shall alarm within .05 seconds of the exact time period specified up to
the maximum timer duration allowed. |
N8 |
Performance: The
microwave oven shall begin the cooking process within .1 seconds of
final key depression. |
N9 |
Performance: The
microwave oven shall provide power at the specified power level within
a tolerance of +/- 1 Watt. |
|
Functional Requirements
|
Each time a keypad
button is pressed a tone shall sound. |
|
A tone shall sound each
time the door is opened or closed. |
|
When the microwave oven
is powered on it shall default to the clock function. |
|
The microwave software
shall support the following functions as described in more detail in
the requirements that follow: a) F4.1: Clock b) F4.2: Timer c) F4.3: Auto Cook Presets d) F4.4: Auto Defrost e) F4.5: Timed Cooking |
|
The active microwave
function shall be identified on the microwave LCD screen. |
|
The clock function of
the microwave oven shall be activated when the Clock keypad button is
pressed. |
|
The default clock value
at power up shall be 12:00. |
|
The clock shall be
operator settable, in one-minute increments, from 12:00 to 11:59. |
|
When the clock function
is active, the current time shall be displayed on the microwave oven
LCD screen. |
|
The initial clock value
shall be settable by using the keys 0 through 9 on the microwave touch
pad. |
|
When the clock function
is active, and the start button is pressed, the clock shall begin
incrementing the current time value at a rate of a minute per
depression of the start button. |
|
A colon symbol
(“:”) shall be displayed between the hours and
minutes numerals on the display. |
|
When the clock is
running, the colon symbol between the hours and minutes numerals on the
display shall be alternately turned on and off each second. |
|
When the clock is not
running, the colon symbol shall not be turned on and off, but shall
remain on. |
|
The Timer function of
the microwave shall be activated when the Timer keypad button is
pressed. |
|
The default timer value
at power up should be 00:00. |
|
The initial timer value
shall be settable by using the keys 0 through 9 on the microwave touch
pad. |
|
If the timer value is
between 99:99 and 00:01 inclusive and the Start button is pressed, the
timer value shall be decremented by one second each second until either
the Stop/Clear keypad is pressed or the timer reaches 00:00. |
|
Within 200 milliseconds
after the timer decrements from the value of 00:01 to the value 00:00 a
buzzer shall sound. |
|
While the timer function
is active, the current timer value shall be displayed on the
microwave’s LCD display. |
|
If the stop/clear button
on the microwave oven keypad is pressed while the timer value is
decrementing, the timer value shall stop decrementing and the timer
value at the time the Stop/Clear button was pushed shall be displayed. |
|
If the timer was stopped
during countdown and the start keypad is pressed the timer value shall
once again begin decrementing from the time at which the timer was
stopped. |
|
If the timer was stopped
during countdown and the stop/clear button is pushed a second time the
timer value should immediately be set to 00:00 and the buzzer shall
sound to indicate that the time countdown has been canceled. |
|
The timer countdown
shall not stop if the microwave door is opened during the countdown. |
|
The microwave shall
provide a series of presets for heating common food items. A preset will be included
for each of the following: microwave popcorn, baked potatoes, pizza,
frozen entrees, fresh vegetables, and liquid beverages. |
|
Each preset button shall
have the capability of having a unique cooking time and power setting
associated with it. |
|
When an operator presses
the start button following after pressing an auto cook preset button: a) the oven shall be turned on at the correct predefined power setting b) the correct predefined cooking time shall be displayed in the LCD screen c) the cooking time shall begin decrementing |
|
The microwave oven shall
provide an auto defrost function that will automatically set the
defrost time and power level for frozen meat items depending on the
weight of the item entered by the user. |
|
The auto defrost
function shall include three settings: Beef, Poultry, and Fish with the
capability of providing a unique power level setting for each of these
types of meat. |
|
A menu shall be
displayed on the LCD screen to provide the operator with the choice of
selecting Beef, Poultry, or Fish. |
|
The auto defrost
function shall require the user to enter the approximate weight of the
meat item being defrosted. |
|
The user shall be
prompted by a message displayed on the LCD to enter the approximate
weight of the meat item using the numeric keypad. |
|
The auto defrost
function shall require that the start key be pressed when the user is
ready to begin the defrosting operation. |
|
Prior to starting the
timed cooking, the operator shall have the capability to choose a power
level from 1 to 9 by first pressing the power level button followed by
one of the numeric keys, 1 through 9. |
|
The default power
setting shall be level 9. |
|
The initial cooking time
value shall be settable using the buttons 0 through 9 on the microwave
oven keypad (AKA touch pad). |
|
The default cooking time
value at power up shall be 00:00. |
|
While the timed cooking
function is active, the current cooking time value shall be displayed
on the LCD screen. |
|
If the cooking time
value is greater than zero and the start keypad button is pressed: a) the oven shall be turned on and b) the cooking time value shall be decremented by one second each second until either the stop/clear button is pressed or until the cooking time value reaches 0:00. |
|
If the stop/clear button
on the microwave keypad is pressed while the oven is on: a) the oven shall be shut off, b) the cooking time value shall stop decrementing, and c) the cooking time value at the time the stop/clear button was pushed shall be displayed on the LCD display. |
|
If the microwave door is
opened during cooking: a) Within 500 milliseconds the oven shall shut off b) a buzzer shall sound c) the cooking time value shall stop decrementing d) the cooking time value when the door was opened shall be displayed on the LCD display. |
|
If cooking was stopped
before the time reached 00:00, either from the door being opened or
from the stop/clear key being pressed, and then (assuming the door is
now closed) the start keypad is pressed: a) the oven shall be turned back on and b) the remaining time to cook value shall once again begin decrementing. |
|
If cooking was stopped
before the time reached 00:00, and the stop/clear button is pushed a
second time: a) the cooking time value shall immediately be set to 00:00 and b) the buzzer shall sound to signify that the cooking has stopped. |
|
Within 200 milliseconds
after the timer decrements from the value of 00:01 to the value 00:00, a) the oven shall be shut off and b) the buzzer shall sound. |
|
When the oven is on, the
operator shall not be allowed to change the power level. |
|
Error codes shall be
displayed for hardware failures. |
No part of this work should be produced or used without the permission of the authors: Michael Turner and Dr. Sharon A White.