TM4T Background 1.3.3 - Task Analysis Techniques - DFD

In any organisation, information gets passed around between employees, departments and systems. This can result in considerable inefficiency if it is done in an inefficient way, and a lot of work goes into designing the best 'route' for the information to follow, often using diagrams like the one shown below (which summarises a simple school-report system). We would expect to see a separate data flow diagram for each process, though we would seek to integrate where possible to ensure efficiency and consistency in our work. The data-flow-diagram shows a series of steps - 1 to 9 - for planning a lesson. The flow of the diagram starts, and ends, with a connector to a different process - the process for delivering a lesson. 

One of the reasons we do this is to be crystal clear on what information is 'flowing' between the individual tasks.The next version shown includes this information, though the names given to the information won't mean much to anyone who isn't closely involved in the process

The diagram above is an example of how a teaching process may be modelled using a data-flow-diagram, but it is just that - a diagramming example and nothing more. It certainly isn't intended to represent the best possible way of planning a lesson, and it certainly isn't expected that you produce diagrams like this yourself, unless you are trying to explain to someone in unequivocal detail how a task should be carried out.