Usability and User Interface Development for Packet Core Network Element

1. Usability and User Interface Development for Packet Core Network Element Author:Taha Othman Supervisor: Prof. Jukka Manner Instructor: Bernardo Di Chiara Place: Nokia Siemens Networks, Espoo 23 May 2012, Espoo Master’s Thesis Seminar Masters Thesis Seminar Masters Thesis Seminar

2. Contents • Background • User Centered Design • Objective • Usability • Usability Engineering Lifecycle • Result • Solutions • Conclusion • Future work Masters Thesis Seminar Masters Thesis Seminar

3. Background According to Alan Cooper: “Most software conforms to implementation models”. “User interfaces that conform to implementation models are bad” In this thesis, the user will be taken into consideration in all activities: The UCD (user-centered design) is used Masters Thesis Seminar Masters Thesis Seminar

4. User -Centred Design Masters Thesis Seminar Masters Thesis Seminar

5. Objective To Create a user interface for the configuration management of SGSN • Create use case. • Benchmarking • Design • Prototype • Usability testing Masters Thesis Seminar Masters Thesis Seminar

6. Usability It is a measurement of different attributes users experience when using a user interface: • Learnability • Efficiency • Memorability • Errors • Satisfaction Masters Thesis Seminar Masters Thesis Seminar

7. Usability Engineering Lifecycle Masters Thesis Seminar Masters Thesis Seminar

8. Defining Use Cases • External interfaces: • Gr • Gs • Iu • Features: • Statistics • Tracing • Charging Masters Thesis Seminar

9. Benchmarking Masters Thesis Seminar

10. Setting Usability Goals • The structure of CLI must be organized in a logical way • The information must be present in a clear way on the screen • The terminology and information must be consistent in CLI • CLI learning experience must be easier and learning time is easier • CLI must be designed in a way that reduces the effort needed by the user to memorize • CLI must provide proper help and proper feedback in case of successful and unsuccessful scenarios Masters Thesis Seminar

11. Design 1/4: The principle of metaphor • “Borrowing behaviors from systems familiar to the users” • Cisco like structure framework • Framework functionality: • Auto completion • Context sensitive help • Secure CLI access • Executed CLI’s history • Validation for the command structure Masters Thesis Seminar

12. Design 2/4: The principle of coherence • “Consistency refers to unification of the general operation sequence, terminology, components, layout, color and style sheets in the user interface” • This principle is implemented by the following: • Implementing CLI framework • Forming a usability committee • Look and feel guidelines Masters Thesis Seminar

13. Design 3/4 : The principle of grammar • “ A user interface is a kind of language – know what the rules are” • Two constructions: • Action -> Object • Object -> Action • In this study case, “Object -> Action” is implemented: • It is natural way for people to think in object rather than verb • It is more user-oriented as there is a good mapping between CLI structure and user’s conceptual model Masters Thesis Seminar

14. Design 4/4 : Other design principle • The principle of user profiling • Strive for simplicity • The principle of reducing memory load • The principle of help • The principle of informative feedback Masters Thesis Seminar

15. CLI structure <domain> <operation> [rest of the command] • domain: the first token determining the functional area • operation: the verb executed on the domain • rest of command: optional tokens that can be decided for each command • Example: sgsn interface gr-ss7 protocols mtp signaling-link configure <parameters> Masters Thesis Seminar

16. Prototype • The prototype is implemented for the mtp layer of SS7 protocol in Gr interface Masters Thesis Seminar

17. Usability testing • The survey was sent to 10 engineers • The respondents were 4 engineers. • Two type of questions: • Self reported questions: • Overall reaction • CLI structure • Layout and screen • Terminology and CLI information • Learning • Open-ended questions: • Free comments • List most negative aspects • List most positive aspects Masters Thesis Seminar

18. Result Masters Thesis Seminar

19. Problems • The same commands are present under different domain • The CLI screen is crowded with information • Help is not enough • “display all” command is missing Masters Thesis Seminar

20. Solutions • Reduce 3 levels from the structure: • “sgsn interface gr-ss7 protocols mtp” • It becomes “sgsn mtp” • New domain, monitor: • sgsn monitor display <signaling-link><all> • sgsn monitor display <ip-configuration> • Creating new commands: • clear_screen • CLI look and feel • Reduce the length of prompt Masters Thesis Seminar

21. Conclusion • It was difficult to identify the real usability issues in the new CLI because of the small numbers of evaluators • The satisfaction of the evaluators varied from one aspect to another: • Positive: • Learning experience • CLI structure • Consistency • Recovering from error situations • Negative: • Screen and layout • Help provide in the CLI Masters Thesis Seminar

22. Future work • Implementing the proposed solutions and conduct another usability survey Masters Thesis Seminar

23. Thank You! Masters Thesis Seminar