Use Cases – an Introduction Sriram Sethuraman Business Analyst SCB group

Agenda __________________________ FSD in plain text format – a sample Limitations of FSD in plain text format The Use Cases – what is it? ◦ Actors, Preconditions, Basic/Alternate flows, etc A sample Use Case with allied components Advantages ad Disadvantages of Use Cases

Take away from this session… __________________________ What are Use Cases A typical Use case sample Components that add granularity to Use Cases Value proposition of Use Cases Where Use Cases might not fit in?

What we shall not be looking at in this session… How to write a best Use Case How to identify different scenarios in a Use Case How to identify business rules Validate the correctness of the functional requirement in the sample use case

A sample business requirement Business Requirement (excerpts from BRD) Allow cash withdrawal through ATMs A customer can withdrawal up to the available balance in the account A customer can only withdraw a maximum of Rs in a day.

Functional Specifications (FSD in plain text) a)The system must allow customers to withdrawal cash from his accounts through ATMs b) The daily allowed limit for withdrawal per customer will be Rs.15,000 c)The system must allow customer to withdraw cash only up to the available balance in the account d) The system must throw an error when the withdrawal amount exceeds the available balance in the account

Limitations of FSD in plain text format The template doesn’t mandate the BA to capture all possible details of a functional requirement Subjective – as it depends on the individual to capture all details of a requirement No ‘end to end’ flow Might be ambiguous if not captured properly e.g. if we say a maximum of Rs in a day, can it only be through one withdrawal or multiple withdrawals amounting to Rs.15000

Use Cases It is a sequence of steps (event flows) describing the interaction between one or more actors and the system to achieve a goal that yields a results of value to one or more stakeholders Actors ◦ Primary, Secondary Pre-condition Post-condition

Sample Use case and its allied components…

Why Use Cases… Scope ◦ Clearly defines the scope at high level Reduces complexity ◦ Focuses on user functions Early user validation All stakeholders will be able to verify the requirements

Why Use Cases(continuation) Template facilitates BA to capture ◦ all possible scenarios ◦ end to end flow ◦ the interfacing system details With allied components(Business Rules, Data elements etc) ◦ Captures all finer details ◦ Reduces ambiguity ◦ Removes subjectivity

Disadvantages… Without the allied components, it is only a high level requirement Takes longer time to capture for first time With all allied components, it becomes little difficult for stakeholders to comprehend the requirements Use Cases not a best fit when it doesn’t involve interaction between an actor and a system e.g. batch processing

Q&A

Thank you…..