Software Re-engineering Source Code Translation The Re-Engineering Process Forward & Reverse Engineering

2. Group Members
 Ali Raza Saleem
 Haf iz Abdul Rehman
 Mobeen-ur-Rehman
 Asad Mirza

3. Source code translation
Reverse Engineering
Software Re-
engineering

4. Software re-engineering
 Reor ganising and modif ying
exist ing sof t war e syst ems t o
make t hem more maint ainable

5. Topics covered
 Source code t ranslat ion
 Reverse engineering

6. System re-engineering
 Re-st ruct ur ing or r e-writ ing par t or
all of a
legacy syst em wit hout changing it s
f unct ionalit y
 Applicable wher e some but not all
sub-syst ems
of a lar ger syst em r equire f r equent
maint enance
 Re-engineering involves adding ef f ort
t o make
t hem easier t o maint ain. The syst em

7. When to re-engineer
 When syst em changes are most ly
rest r ict ed t o
par t of t he syst em t hen r e-engineer
t hat par t
 When har dware or sof t war e suppor t
becomes
out -dat ed

8. Re-engineering advantages
 Reduced risk
 There is a high r isk in new sof t ware
development . Ther e may be
development problems, st af f ing
pr oblems and specif icat ion problems
 Reduced cost
 The cost of re-engineering is of t en

9. Business process re-
engineering
 Concerned wit h r e-designing business
pr ocesses t o make t hem mor e responsive
and mor e ef f icient
 Of t en r eliant on t he int roduct ion of new
comput er syst ems t o suppor t t he
revised pr ocesses
 May f or ce sof t war e r e-engineering as

10. Forward engineering and re-
engineering

11. The re-engineering process

12. Re-engineering cost factors
 The qualit y of t he sof t war e t o be r e-
engineer ed
 The t ool support available f or r e-
engineer ing
 The ext ent of t he dat a conver sion
which is r equir ed

13. Re-engineering approaches

14. Source code translation
 I nvolves conver t ing t he code f r om one
language (or language version) t o
anot her e.g. FORTRAN t o C
 May be necessary because of :
 Hardware plat f orm updat e
 St af f skill short ages
 Organisat ional policy changes

15. The program translation
process

16. Reverse engineering
 Analysing sof t war e wit h a view t o
under st anding it s design and
specif icat ion
 May be part of a re-engineer ing process
but may also be used t o re-specif y a
syst em f or re-implement at ion
 Pr ogr am under st anding t ools (browsers,

17. The reverse engineering
process

18. Reverse engineering
 Rever se engineer ing of t en pr ecedes re-
engineer ing but is somet imes wort hwhile
in it s own right
 The design and specif icat ion of a syst em
may be reverse engineered so t hat t hey can
be an input t o t he requirement s
specif icat ion process f or t he syst em’s
replacement

19. Key points
 The obj ect ive of re-engineering is t o improve t he
syst em st ruct ure t o make it easier t o underst and and
maint ain
 The re-engineering process involves source code
t ranslat ion, reverse engineering, program st ruct ure
improvement , program modularisat ion and dat a re-
engineering
 Source code t ranslat ion is t he aut omat ic conversion of
of program in one language t o anot her

20. Key points
 Reverse engineering is t he process of deriving t he
syst em design and specif icat ion f rom it s source code
 Program st ruct ure improvement replaces unst ruct ured
cont rol const ruct s wit h while loops and simple
condit ionals
 Program modularisat ion involves reorganisat ion t o group
relat ed it ems
 Dat a re-engineering may be necessary because of
inconsist ent dat a management