Go with the Flow (Part 3)
Hi there again, we are now half way there in terms of blog entries, goes quick doesn’t? So this week as promised Il explain what exactly a DFD is and what would its differences be against a ordinary flow chart. And just in case any of forgot DFD means Data Flow Diagram.
Okay think of it this way flow charts are the big oak and DFDs are the specific branch. So DFDs are specific to information systems as oppose to my example of getting out of bed back in part 1.
So think of the ATM example, buying cinema tickets, purchasing clothes online or scanners at shops
Now there is one more thing that makes DFDs unique to other flow charts. Its has similar symbols of flow charts in the entities, the processes and data flows. Now here is the unique difference in the DFDs you also have a symbol for data stores. This is for information systems that want to keep track off all data. Like buying products at online. Say “River Island” wanted to know which clothing was there most popular they could have an information system scanner in store and you would be able to buy it from scanning the item, and machine keep record of the individual item. Now the data is stored
There is type of DFD called Context DFD. It’s basically a mini DFD. It so people can take a quick glance at how the information system operates
Il explain more about DFD’s mechanics next week