1. Requirements Walk-through
COMP208/214/215/216 Lecture 4
Requirements Walk-through

2. Requirements Review Meeting
This meeting reviews the outputs of the first three steps of the method in Connolly and Begg.
It will review the 7 items of documentation which should be produced in this phase of the project
This review counts as 15% of your group mark.

3. Organisation Details
The Requirement Specification Walkthroughs will take place in week 4 (between 20– 24 February 2012)
Teams are responsible for arranging a time for the review
Send to me, cc-ed to all group members
Make your booking by Friday 17 February.
The documentation to be reviewed must be submitted to the school office on or before 12 noon Friday 17 February
Reviews will typically last minutes, well organised submission clearly written and fully complete will have an easier time at review

4. Documentation Required
Mission statement
Mission objectives
System Boundary Diagram
User Views and Their Requirements
Transaction Requirements (if appropriate)
Systems Specification
Project Gantt Chart.
Descriptions and examples of items 1-6 are in
Connolly and Begg Chapters 3 and 4 (1st edition) or Chapter 6 (2nd edition).

5. Format of the Review For each deliverable:
A team member introduces the item
The reviewer may ask questions for clarification
Team replies to questions
The reviewer may make comments
Team may briefly respond to comments
A Report Form will be completed by the reviewer and given to the team as soon as possible.

6. Mission Statement
The mission statement is a single sentence which defines the overall purpose of the database: what it is for
It should be clear and unambiguous
It is not a list of functions that the database will perform: it is the reasons why those functions are wanted.
StayHome example: p 64 of Connolly and Begg (p129 in 2nd edition).

7. Mission Objectives
The Mission Objectives statement is a list of particular tasks that the system will support
Each objective begins with an infinitive
To maintain/ perform/ track/ find/ report/ show/ record etc.
Indicates which data items to be used
Tasks supported - not who will do them
Should be as comprehensive as possible.
Example: Figure 4.8 of Connolly and Begg (Figure 6.8 in 2nd edition).

8. Systems Boundary Diagram
The intention of this diagram is to represent the main types of data relevant to the system
The boundary shows what will be included in the system and what will be not. Data may be:
In the system
Available on other systems to which links will be provided
Not to be available at all.
Figure 4.9 of Connolly and Begg provides an example (Figure 6.9 in 2nd edition).

9. User Views and Requirements
Purpose: to identify the major classes of user and the functions they will use.
e.g. administrator, teacher, pupil:
Administrator maintains the database: views, adds, modifies, deletes records
Teacher customises the database: views and adds records, but doesn’t modify or delete records
Pupil uses the database: only views records.
In other applications, different users may maintain and use different data items.

10. More on User Views
We are producing a list of users and, for each user, the functions they need:
Functions should relate to mission objectives:
Every user function should be included in mission objectives
Every mission objective should relate to some user function
Several users may use the same function.
Example at figure 4.10 of Connolly and Begg (Figure 6.10 in 2nd edition).

11. Other roles Developer account System admin (different from admin)
Same as standard user but…
Allows for special test cases
E.g. credit card
(not LUHN tested)
System admin (different from admin)
Technical admin account
Allows backup and re-configuration

12. Other issues Logging Error logging Audit/security logging
All transactions (cash or otherwise should be logged, i.e. stored in database table)
E.g.
log id,Userid , amount, description, payment id
100, 1045, 100,”Purchase of book”,12
Error logging
Store in error log on database all bug logs
Audit/security logging
Store in log, if when user gets password wrong, or wrong 3 times (you decide)

13. System monitoring How do you keep your system up Checkout … Pingdom
What will you do if your payment server goes down…?
Backup services and fail over

14. Connecting to external services
Payments
CC card
Paypal
Google
Password forget
SMS
Reminders and password forget

15. Transaction and Transactional Requirements
Each user view will involve certain transactions, stipulating how the data is to be used
There are three broad categories:
Data entry: every data item needs to be created somewhere
Data update and deletion
Data queries
Transactions should be related to the user view to ensure all functions are supported
Do transactions needed to be atomic

16. Data Requirements
Although not required for review at this stage you may find it helpful to list the information required by each user:
e.g. we need information on departments, staff, courses
departments have a name, head, building, etc
staff have a name, department, office, etc
courses have a code, level, teacher, etc
This will be refined at the design stage.

17. Checks
Use the data requirements to check the transaction requirements:
All data should be created somewhere
All data should be used in some query
If not - what is it included for?
All queries should have the data required to support them in the data specification.

18. System Requirements Various aspects to cover here:
Initial Database Size
Rate of Growth
Expected type and frequency of searches
Network and Access requirements
Performance
Security
Back-up and Recovery
Legal Issues
Detail required will vary according to application and environment
e.g. a stand alone single user application will need less detail on access and requirements than a commercial multi-user system.

19. Project Gantt Chart
A chart showing the major milestones, tasks and deliverables of the project and when they are scheduled
You need to report your past progress and future plans.
You will need to update this chart for each Walkthrough.

20. Summary By FRIDAY 17 FEBRUARY 2012 You must book your meeting.
You must supply the requirement documents
During the week 20/02/ /02/12
You must attend the review meeting
Please attend the meeting punctually
This review is an important milestone: it lays the foundations for the project.