IS3320 Developing and Using Management Information SystemsLecture 13: Flow-Charts 1

Rob Gleasure

R.Gleasure@ucc.iewww.robgleasure.com

IS3320

Today’s lecture What is a flowchart? Why would we use a flowchart? When would we use a flowchart? What notation is used in a flowchart? How do we draw a flowchart from some narrative? Exercise

What is a Flowchart?

Takes an algorithm (process) and illustrates it with a set of graphical symbols In other words, a visualisation of some process

Why would we use a Flowchart? Many of the same reasons we create use cases

Ability to stay user-centred in our design Ability to communicate Ability to abstract Ability to tie testing back to key requirements

The also let us Decompose and communicate processes with a little more

sophistication than just sequencing them out in text form Plan out how an application will actually run to address the

various use cases Spot redundancies, bottlenecks and circular processes

When would we use a Flowchart? Useful during both analysis and design stages

During analysis it lets you try to figure out the ‘as-is’ behaviour that you may be seeking to replace. It also creates a useful way of exploring a system by building outwards from the practices

During design it lets you move from abstract ideas of how various actors and technologies will interact to a more lucid, algorithmic approach. It also acts as a useful communication and idea testing tool for programmers (who deal in algorithms), designers, and users

What notation/symbols are used for a Flowchart?

Terminal symbol, used to mark beginnings and ends of process

Process symbol, used whenever the system or the system’s data is being used or manipulated

Decision symbol, used when different selections/conditions invoke different paths

Flow line, used to indicate sequential movement from one process to another

Input/output symbol, used whenever data is being input or output

Document symbol, used when a user is storing or reading data from some document or other source

What notation/symbols are used for a Flowchart (continued…) Subroutine symbol, used to identify an operation in a

separate flowchart segment

On-page connector symbol, used to connect remote flowchart portions on the same page (this is messy)

Off-page connector symbol, used to connect remote flowchart portions on a separate page

Comment symbol, used to add some text to describe or clarify some aspect of the flowchart

Page 2Page 1

Example: ATM Balance Query

Start

Stop

Show balance

Check match (card, pin)

Input user card and pin

Is match?

YES

Alert user to errorNO

Check match (card, pin)

Return match details

Get card account details

Compare pin with

stored pin

How do we draw a flowchart from some narrative or some use case? We will typically analyse narratives and use cases for two types of object

Verbs: these hint towards parts of an actual process and allow us to begin to formulate the basic algorithm

Nouns: these can be actors or objects Knowing the objects lets us know the types of data and resources used in each process,

which form the foundation over which these processes interact Knowing the actors will add context to process flows and hep to link them together under

different types of organizational functions/responsibilities. This lets us map the process across ‘swim lanes’

Adding ‘swim lanes’ to flowcharts Swim lanes divide a flowchart into horizontal or vertical bands

Each band represents the subprocesses associated with some actor or organizational function, e.g. employee, HR, etc.

This captures the different areas where processes and data are handed off between different actors or organizational functions This is very useful in practice!

Example of ‘swim lanes’

Image from story-games.com

Swim lanes example narrative Take the case of student applying for a course – this process not only involves a number of

different steps, but also different actors Students submit an application Administration check if the application is complete, returning the application to the student if not A Registrar checks if the students is eligible according to the minimum requirements Faculty decide whether or not an eligible student is suitable If the student is not eligible according to the registrar, or not suitable according to Faculty,

Administration send the student a rejection letter If the student is eligible and suitable, Administration send the student an acceptance letter

Swim lanes example narrative Who are the actors in this narrative?

How could the process be mapped out across these different actors using swim lanes?

Exercise: How do Google Make Money? Answer: “primarily by delivering relevant, cost-effective online advertising”

AdWords* Advertising space is placed above, beside, or below the list of search

results Google displays for a some query This advertising space is auctioned off for specific query types Both cost-per-click advertising is offered, as well as cost-per-

thousand-impressions advertising

* AdSense is also used, which allows website administrators to place ads on their website and track performance, but this is secondary to AdWords for Google in terms of revenue

Exercise: How do Google Make Money? In groups of 2-3…

Draw a flowchart for how you think AdWorks might work for pay-per-click advertising

Note any possible changes to the process (as you imagine to exist currently) that you think might be promising

Want to read more?

Google AdWords site https://accounts.google.com/ServiceLogin?

service=adwords&continue=https://adwords.google.com/um/identity?ltmpl%3Djfk&hl=en_GB&ltmpl=jfk&passive=0&skipvpage=true

Investopedia article on AdWords and Google http://www.investopedia.com/stock-analysis/2012/what-does-google-

actually-make-money-from-goog1121.aspx