Page 257 - Software and Systems Requirements Engineering in Practice

ç ç 3 O F T W A R E ç ç 3 Y S T E M S ç 2 E Q U I R E M E N T S ç % N G I N E E R I N G ç ) N ç 0 R A C T I C E

OHN WAS A RECENT 0URDUE GRADUATE WHO FOR HIS FIRST JOB WAS
ASSIGNED TO TEST A REAL TIME VEHICLE CONTROL SYSTEM (E HAD STUDIED
*THE h6v MODEL IN SCHOOL AND HAD WRITTEN SOME SMALL TEST PROGRAMS
WITH A TEAM OF STUDENTS "UT HE WAS NEVER EXPOSED TO A SYSTEM AS
LARGE AND TIME CRITICAL AS THE ONE HE WAS ABOUT TO TEST (E KNEW THAT
HE SHOULD hTEST TO VALIDATE THE SYSTEM REQUIREMENTS v BUT HE HAD A
DIFFICULT TIME UNDERSTANDING THE REQUIREMENTS AS HE BROWSED THROUGH
THE REQUIREMENTS DATABASE &URTHERMORE HIS BOSS EXPLAINED TO HIM
THAT THE PROJECT WAS BEHIND SCHEDULE AND HE MAY BE ASKED TO WORK
SOME EVENINGS AND WEEKENDS AS THEY WERE TRYING TO GET THROUGH THEIR
TEST SUITE IN A SHORTER TIME THAN ORIGINALLY PLANNED BY WORKING
MULTIPLE SHIFTS *OHN BEGAN TO BECOME CONCERNED FOR HIS SOCIAL LIFE
SINCE HE REALIZED HE WILL BE SPENDING MANY HOURS IN THE TEST LAB
4HIS CHAPTER DEALS WITH SYSTEM TESTING THAT IS BASED ON
REQUIREMENTS )T INTRODUCES CONCEPTS AND DISCUSSES TECHNIQUES THAT CAN
BE SUCCESSFULLY USED TO CREATE TEST CASES USING SOME OF THE 2% ARTIFACTS
)T DISCUSSES MODEL BASED TESTING -"4 FOCUSING ON THE TYPES OF
2% MODELS AND SPECIFICATIONS THAT ARE USEFUL TO THE TEST ENGINEER

"ACKGROUND
3OFTWARE 4ESTING IS THE PROCESS OF EXECUTING SOFTWARE WITH THE INTENT OF
FINDING ERRORS ;-YERS = AND IT BASICALLY SUPPORTS VALIDATION
VERIFICATION 6 6 ACTIVITIES 4HE #--) #APABILITY -ATURITY -ODEL
)NTEGRATION GUIDELINES DESCRIBE VALIDATION AS THE ACTIVITY THAT
DEMONSTRATES IF A PRODUCT WILL MEET ITS INTENDED USE AND VERIFICATION
AS THE ACTIVITY FOR ENSURING THAT THE PRODUCT MEETS SPECIFIED
REQUIREMENTS 6ERIFICATION IS MAINLY DONE BY THE DEVELOPMENT AND
TESTING TEAMS AND IT TYPICALLY INCLUDES OTHER NON TESTING BASED
TECHNIQUES SUCH AS PEER REVIEWS INSPECTIONS AND DEBUGGING /N THE
OTHER HAND VALIDATION ACTIVITIES ARE BASED ON SPECIFIED REQUIREMENTS
AND THE REQUIREMENTS ENGINEERS ARE VERY MUCH INVOLVED 4HUS THERE
IS A STRONG LINK BETWEEN TESTING AND REQUIREMENTS ENGINEERING 4EST
ENGINEERS MUST UNDERSTAND THE REQUIREMENTS SO THAT THEY CAN VALIDATE
THAT THE SYSTEM S BEHAVIOR IS SUCH THAT IT MEETS THE REQUIREMENTS
6ALIDATION ACTIVITIES CAN BE BASED ON BOTH FUNCTIONAL AND NONFUNCTIONAL
REQUIREMENTS
4HE ROLE OF TESTING TO REQUIREMENTS VALIDATION CAN BE SEEN IN
VARIOUS LIFE CYCLE MODELS SUCH AS THE h6v MODEL ;6-ODEL 84 =
4ESTING IS DONE TO VALIDATE LIFE CYCLE ARTIFACTS THAT ARE GENERATED BY
REQUIREMENTS ENGINEERING AND DESIGN &OR EXAMPLE TESTERS WILL USE A
REQUIREMENTS SPECIFICATION AS THE STARTING POINT FOR DEFINING THEIR
ACCEPTANCE TEST SUITE )DEALLY THERE SHOULD BE A SYSTEM TEST SUITE THAT