Page 231 - Software and Systems Requirements Engineering in Practice
P. 231

R
                                              E

                                                ç
                                          A
                                         H
                                             T
                                            P
        ç ç                             # # H A P T E R ç     ç ç  2  E  Q  U  I  R  E  M  E  N  T  S  ç  -  A  N  A  G  E  M  E  N  T  ç
                                                     2 E Q U I R E M E N T S ç - A N A G E M E N T ç

                  /Þ«iʜvÊ ˜>ÞÈà   iÃVÀˆ«Ìˆœ˜              *ÀœViÃÃiÃÊ-Õ««œÀÌi`
                   “«>VÌÊ>˜>ÞÈà   œœÜʈ˜Vœ“ˆ˜}ʏˆ˜ŽÃ]ÊÌœÊ   …>˜}iʓ>˜>}i“i˜Ì
                                   >˜ÃÜiÀÊ̅iʵÕiÃ̈œ˜\ʺ7…>ÌÊ
                                   ˆvÊ̅ˆÃÊÜiÀiÊ̜ÊV…>˜}i¶»
                   iÀˆÛ>̈œ˜Ê>˜>ÞÈà   œœÜʜÕÌ}œˆ˜}ʏˆ˜ŽÃ]ÊÌœÊ   œÃ̇Li˜ivˆÌÊ>˜>ÞÈÃ
                                   >˜ÃÜiÀÊ̅iʵÕiÃ̈œ˜\ʺ7…ÞÊ
                                   ˆÃÊ̅ˆÃʅiÀi¶»
                   œÛiÀ>}iÊ>˜>ÞÈà   œÕ˜ÌÊÃÌ>Ìi“i˜ÌÃÊ̅>Ìʅ>ÛiÊ   i˜iÀ>Êi˜}ˆ˜iiÀˆ˜}]Ê
                                   ˆ˜ŽÃ]Ê̜Ê>˜ÃÜiÀÊ̅iʵÕiÃ̈œ˜\Ê  “>˜>}i“i˜ÌÊ
                                   º >ÛiÊ ÊVœÛiÀi`ÊiÛiÀÞ̅ˆ˜}¶»Ê  Ài«œÀ̈˜}
                                    œÃÌʜvÌi˜ÊÕÃi`Ê>ÃÊ>Ê
                                   “i>ÃÕÀiʜvÊ«Àœ}ÀiÃð
                 /    ÊÇ°ÓÊ  >ˆ˜Ê/Þ«iÃʜvÊ, Ê ˜>ÞÈÃÊ ˜ˆÌˆ>Ìi`ÊLÞÊ>Ê

                      )MPACT !NALYSIS
                      4HE  OBJECTIVE  OF  IMPACT  ANALYSIS  IS  TO  DETERMINE  THE  FINANCIAL
                      RESOURCE  OR TEMPORAL COST OF A CHANGE REQUEST OR NEW FEATURE  4O DO
                      THIS  THE RESPONSIBLE ##" MEMBER  USUALLY THE ARCHITECT  OR HIS HER
                      DELEGATE MUST TRACE FROM THE IMPACTED FEATURES TO THE ACTUAL SYSTEM
                      DESIGN IN ORDER TO DETERMINE HOW SIGNIFICANT ANY MODIFICATIONS OR
                      ENHANCEMENTS WOULD BE  AND THEN FROM THAT DERIVE THE COST AND
                      RISK OF SUCH MODIFICATIONS
                         !NALYZING THE IMPACT OF A CHANGE REQUEST REQUIRES TRACING DOWN
                      THE  LEFT  SIDE  OF  THE  EXAMPLE  ENGINEERING  PROJECT  TRACEABILITY  MODEL
                       SEE LATER &IGURE       4RACES GO FROM REQUIREMENTS m DESIGN  )F THE
                      REQUIREMENT  BEING  ANALYZED  IS  NONFUNCTIONAL   E G    PERFORMANCE
                      CAPACITY    THEN  ADDITIONAL  EFFORT  MAY  BE  REQUIRED  TO  SIMULATE  THE
                      IMPACT OF THE PROPOSED CHANGE TO DETERMINE IF IT IS FEASIBLE


                   #USTOMER -ANAGEMENT AND #HANGE #ONTROL
                   ! SOFTWARE DEVELOPER WAS SENT TO DO INSTALLATION WORK ON A CONTROL
                   SYSTEM FOR AN OFFSHORE OIL PLATFORM  7HILE THE DEVELOPER WAS SEATED AT
                   A  TERMINAL  PERFORMING  A  SOFTWARE  INSTALLATION   THE  CUSTOMER
                   REPRESENTATIVE SAT DOWN ALONGSIDE HIM AND ASKED IF A SPECIFIC CHANGE
                   WAS  FEASIBLE   4HE  DEVELOPER  REPLIED  THAT  IT  WAS   4HE  CUSTOMER  THEN
                   ASKED HOW MUCH IT WOULD COST  AND THE DEVELOPER  NOT GIVING IT MUCH
                   THOUGHT  SAID hA FEW DAYS v 3EVERAL WEEKS LATER THE PROJECT MANAGER
                   RECEIVED A LETTER OF UNDERSTANDING FROM THE CLIENT STATING THAT THERE HAD
                   BEEN AGREEMENT BETWEEN OUR REPRESENTATIVE  THE DEVELOPER  AND THE
                   CUSTOMER  TO  MAKE  THE  CHANGE  AT  NO  CHARGE   5PON  DOING  AN  IMPACT
                   ANALYSIS  IT WAS DETERMINED THAT THE COST OF THE CHANGE WOULD COMPLETELY
                   WIPE OUT THE PROJECT CONTINGENCY  4HE DEVELOPER BARELY REMEMBERED
                   THE CONVERSATION  (EATED DISCUSSIONS WITH THE CUSTOMER THEN ENSUED
   226   227   228   229   230   231   232   233   234   235   236