1. Software Integration Software Integration IT323 - Software Engineering 2 Tutorial

2. Example-1 Given a simple program that reads a string inverts it then writes it the structure of this program is Where boxes indicate modules and links indicate module calling Main ReadInvertWrite S S S.inv

3. 1. Bottom-up Integration Bottom-up Integration Algorithm – Integrates components at the lowest levels then adds functional components when going to the upper levels.

4. 1. Bottom-up Integration Bottom-up Integration Algorithm 1.Construct drivers for low level modules. 2.Execute and test each driver separately. 3.Remove drivers and combine modules moving upward into clusters that perform a specific software subfunction. When the main module is reached go to 5) 4.Construct a driver per cluster. Go to 2) 5.Stop when the whole system structure is built and no drivers remain

5. 1. Bottom-up Integration ReadInvertWrite Step 1 Step 2 Step 3 drivers

6. 1. Bottom-up Integration Step1 – Test the “Read” module through its driver void Read(String s) { Output(“enter string”); Input(S); } void main(){ String s; Read (s); Output(“the string read is”, s) }

7. 1. Bottom-up Integration Step2 – Test the “Invert” module through its driver void invert(string r, string s)) { For (i=0; i<s.length ; i++) r[i]=s[s.length-1-i]; } void main(){ String r,s; s=”Example text”; Invert(r,s); Output(“text to be inverted”,s, ”its inverse”, r); }

8. 1. Bottom-up Integration Step3 – Test the “Write” module through its driver void write(string r) { Output(“inverted string is”, r); } void main(){ String r; r=”Example text”; Write(r); }

9. 1. Bottom-up Integration Step4 : void Read(String S){ Output(“enter string”); Input(S); } void invert(invert(string r, string s)){ For (i=0;i<s.length;i++) R[i]=S[s.length-i-1] } void write(string r){ Output(“inverted string is”,r); } void main() { String s,r; Read(s); Invert(s,r); Write(s); }

10. 2. Top-down integration Top-down Integration Algorithm – Develops the skeleton of the system and populate it with components.

11. 2. Top-down integration

12. Read

13. 2. Top-down integration ReadInvert

14. 2. Top-down integration ReadInvertWrite

15. 2. Top-down integration Top-down Integration Algorithm 1.Use Main control module as a test driver and substitute all modules that are directly subordinate to it by stubs. 2.Depending on the integration approach selected (depth first or breadth first), choose a stub and replace it by a real module. 3.Tests are conducted after replacement of a stub by a real module. 4.While there exist stubs in the system, go to step 2(loop) 5.Stop when the whole system structure is built and no stubs remain.

16. 2. Top-down integration Step1 void SRead(string s) % read stub %{ Output(“I am in READ module”); S=”Example string”; } void SInvert(string s, string r) % invert stub %{ Output(“I am in Invert module”); Output(S); r=”Example output string”; } void Swrite(string r) % write stub %{ Output(“I am in write module”); Output(r); } void main(){ String r,s; Sread(s); Sinvert(s,r); Swrite(r); }

17. 2. Top-down integration Step2 – Replacing Sread (stub of read procedure) by its real Read and keep the rest unchanged void Read(string s){ Output(“enter string”); Input(S); } void SInvert(string s, string r) % invert stub %{ Output(“I am in Invert module”); Output(S); r=”Example output string”; } void Swrite(string r) % write stub %{ Output(“I am in write module”); Output(r); } void main(){ String r,s; Read(s); Sinvert(s,r); Swrite(r); }

18. 2. Top-down integration Step3 – Replacing Sinvert and keep the rest unchanged void Read(string s){ Output(“enter string”); Input(S); } void Invert(string s, string r) { For (i=0;i<s.length;i++) R[i]=S[s.length-i-1] } void Swrite(string r) % write stub %{ Output(“I am in write module”); Output(r); } void main(){ String r,s; Read(s); Invert(s,r); Swrite(r); }

19. 2. Top-down integration Step4 – Replace all stubs by their real & integrate the system void Read(string s){ Output(“enter string”); Input(S); } void Invert(string s, string r) { For (i=0;i<s.length;i++) R[i]=S[s.length-i-1] } void Write(string r){ Output(“inverted string is”,r); } void main(){ String r,s; Read(s); Invert(s,r); Write(r); }

20. Example -2 Given the software system skeleton (Structured Chart)

21. Example -2 Use the above skeleton to identify the testing strategy indicated by the sequences given. {F};{G};{H};{I};{J};{K};{B,F,G,H};{E,I,J,K};{A,B,C,D,E,F,G,H,I,J,K} –T–Top-down testing –B–Bottom-up testing –B–Big-bang testing {A};{A,B};{A,B,C}; {A,B,C,D};{A,B,C,D,E};{A,B,C,D,E,F};{A,B,C,D,E,F,G};{A,B,C,D,E,F,G,H}; {A,B,C,D,E,F,G,H,I}; {A,B,C,D,E,F,G,H,I,J}; {A,B,C,D,E,F,G,H,I,J,K} –T–Top-down testing –B–Bottom-up testing –B–Big-bang testing