*Urgent* Need reference for DFD & ERD diagram

Posted on 2009-04-27
Medium Priority
Last Modified: 2012-05-06
Hi guys.

I am currently working on my assignment.
Can anyone give me reference to similar diagrams? DFD & ERD
The questions

Case Study 1
Projects, Inc. is an engineering firm with approximately 500 engineers of different types. The company keeps records on all employees, their skills, projects assigned and departments worked in. New employees are hired by the personnel manager based on data in an application form and evaluations collected from other managers who interview the job candidates. Prospective employees may apply anytime and these applications are kept in an applicant file.
Engineering managers notify the personnel manager when a job opens and list the characteristics necessary to be eligible for the job. The personnel manager compares the qualifications of the available pool of applicants (in the applicant file) with the characteristics of an open job and then schedules interviews between the manager in charge of the open position and the three best candidates from the pool.
After receiving evaluation on each interview from the manager, the personnel manager makes the hiring decision based upon the evaluations and applications of the candidates and the characteristics of the job, and then notifies the interviewees and the manager about the decision.
Applications of rejected applicants are retained for one year, after which time the application is purged.  The personnel manager goes through the files each month to purge applications over one year old.  When hired, a new engineer completes a nondisclosure agreement, which is filed with other information about the employee.
Draw a context and level 0 data flow diagram to represent the narrative. Please state your assumptions clearly.      

Case Study 3
Draw an ERD diagram for the following:                              

MDIS, a private university, has several faculties and each faculty is headed by a Head of Faculty (HOF). A team of lecturers are assigned to each faculty and each lecturer may teach one or more courses. Each faculty offers several courses, for example, the computer science faculty offers courses in software engineering, human computer interaction, project management etc. The lecturers are able to check on their course schedules published by the faculty 2 weeks before the semester commences.
Question by:moneywell
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Author Comment

ID: 24247786
Can anyone give me real Data flow diagrams of systems? Thanks
LVL 29

Expert Comment

by:Bill Bach
ID: 24252660
A data flow diagram depicts the various inputs and outputs of processes in a graphical form.  It's quite difficult to answer in a text-based forum, without actually drawing the picture and posting it -- which is essentially doing the work for you.

What I can do is give you some tips.  Every process in the DFD needs to have inputs and outputs.  All data that is needed for a process has to come from somewhere, and all outputs have to go somewhere.  Anytime you get data from a static storage location, it's a data store.  Any time it comes from another process, you can connect the processes directly.

In this case, you can clearly see some data stores: Employees, Employee/Projects, Employee/Departments, Employee/Skills, Applications, Evaluations, and so on.  Let's look at the first process defined here -- the "Hiring Process" -- which clearly needs several inputs from Application and Evaluations, with outputs going to the ApplicantFile and (if approved) the Employees file.

Do this for each process independently, first.  Then, make sure that you have enough data for each process.  For example, a New Job Opening process requires information on the Job and on the JobCharacteristics (from the engineering manager), and this information has to be fed to the personnel manager, which then reads the applicant file, and so on.  

Essentially, you are trying to break down the process into small, but meaningful steps.  The concept of a DFD is to help define where data comes and where it goes -- no data should be spontaneously created nor lost in the process map.  Once you have all of this, you can then decide which steps will be monotonous and can easily be done by a computer, and which steps will always be done by a person (this is the human/machine boundary).    You should eventually use just about every word of the text in the description in your diagram to create the data flow.

Author Comment

ID: 24256857
Hi BillBach

Do you have any examples to go through?
LVL 29

Accepted Solution

Bill Bach earned 2000 total points
ID: 24260391
Here's two examples, the first being a Level 0 diagram (what you want) for an computerized quizzing application, and the second being an exploded (level 1) view of the Build Quiz Data element.  These are a bit old (created with a high-end tool for its day in 1990), but you should be able to get the basic idea...

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