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

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.

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 e-mail 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 20-30 minutes, well organised submission clearly written and fully complete will have an easier time at review

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).

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.

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).

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).

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).

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.

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).

Other roles Developer account System admin (different from admin) Same as standard user but… Allows for special test cases E.g. credit card 1234123412341234 (not LUHN tested) System admin (different from admin) Technical admin account Allows backup and re-configuration

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)

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

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

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

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.

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.

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.

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.

Summary By FRIDAY 17 FEBRUARY 2012 You must book your meeting. You must supply the requirement documents During the week 20/02/12 - 24/02/12 You must attend the review meeting Please attend the meeting punctually This review is an important milestone: it lays the foundations for the project.