Data Flow Diagrams. Data and databases - Data Flow Diagrams. Introduction

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1 Data Flow Diagrams Getting learners to understand the contruction of Data Flow Diagrams is the aim of this section Introduction This activity is about constructing Data Flow Diagrams (DFDs). The teacher or trainer introduces the ideas and notation used in DFDs and this is followed by the activity itself which has two stages. The first stage is a role play using a scenario based on a dental practice. Learners play the roles of patients (three), receptionist and dentist. They are given briefing notes to tell them who they are and roughly what they need to do. Others watch the role play and capture the entities, data flows, processes and data stores as the role play progresses. Learners record their findings on flip charts or white boards. You could stop at this point and omit Stage 2 or move on to Stage 2 immediately or at a later date. In Stage 2, after the role play, learners are divided into groups of three or four and given cards with entities, data stores, processes and data flow arrows from which they construct a DFD diagram for the dental practice system. Aims The aim of this session is to enable learners to understand how to construct DFDs and to understand the symbols used in the notation Structured Systems Analysis and Design Method (SSADM). It may be linked to projects that learners are undertaking or are planning. Learning objectives At the end of this session learners will be able to: capture data from a system dynamically recognise and use the symbols required to construct a Data Flow Diagram create a Data Flow Diagram for a given system.

2 Resources Role play material (this needs to be printed, laminated and cut up before the session). Cards used to create a DFD of the dental practice (these need to be printed, laminated and cut up before the session) Learner guidance notes. Flip charts or whiteboards and pens (not provided). Preparation The files which need to be printed and laminated can be found on the Teacher resources CD-ROM in your pack. They can be found on the CD-ROM under Learner activities resources for advanced learning examples. For the files Patient record card and Receipt, print and cut out the three cards. Print the files Dentist, New patient, Existing patient and Receptionist. For the file DFD cards, cut each page so that each symbol or box is separate. You may wish to enlarge the cards if they seem too small. Do the same for DFD blank cards. From the first two pages cut out the individual sets of lines of text as separate items for example: patient record On the next page cut out entries such as: reception enter payment details as single items. On the next page cut out each line of text as a separate item. For the rest of the file cut out everything as separate items You will need a complete set of everything for each group in the session.

3 Teacher and trainer guidance Introduction Before starting this activity learners should be familiar with the concept of DFDs and their use in documentation. They should be familiar with the symbols and understand the use of different levels of DFD. Role play is used to practise data storage and maintenance Stage 1 1. Scenario New patients are asked a series of questions (their name, address, GP s name and surgery, any medication they are currently taking and any allergy details or general health concerns) when they join a dental practice. A receptionist writes these on to a Patient Record Card that is filed in a cabinet. The learner playing the role of new patient needs to understand that they should give this kind of detail to the receptionist. Patients book appointments through the receptionist. The appointments are logged in a page a day diary. Each morning the receptionist checks the diary. For each appointment that day the Patient Record Cards are taken from the filing cabinet and kept by the receptionist. When an existing patient arrives he/she is given their Patient Record Card to take into the dentist. The dentist sees each patient in turn and notes changes to the patient's health details or details of the treatment given during the appointment on the Patient Record Card. After their appointment patients usually have to pay for the consultation. The required fee for treatment is logged onto an Excel spreadsheet. The patient s name, the treatment given and the amount paid is entered onto the spreadsheet. When payment is received, patients are given a paper receipt and the payment is recorded in the spreadsheet. 2. Introduce the activity Select people to play the various roles - three printouts (two existing, one new), one receptionist, one dentist. Hand out the role play material and explain what each person has to do. The central role is the receptionist, so choose this learner carefully. Select

4 someone who will keep the role play going and be able to use their own initiative. Brief one of the learners that they are to play the role of a new patient registering with the dentist. Allocate those not involved in the role play into groups of three and give each group a white board or a flip chart to write on. Tell the groups that their job is to capture the entities, processes, data stores and data flows during the role play. Begin the role play and assist as necessary. The role play begins with one of the patients announcing their arrival to the receptionist. You may find it useful to control the flow of patients through the system to make sure that the observers can record and understand the process. 3. Plenary At the end of the role play, congratulate the players and turn to the observers. Ask the first group to briefly explain what they have recorded. Call for questions and comments. Ask subsequent groups to identify any differences and get them to explain why. Correct any misconceptions as you go through this process. Summarise the findings. Stage 2 - Further practice 1. Form new groups of three or four, including those involved in the role play. Hide the solutions on the boards/flip charts and hand out the materials to each group. Ask them to create a DFD for the dental practice system using the entities, data stores, data flows and processes provided. Give advice and assistance where required. Stage 3 - Plenary 1. Summarise the stages required in the development of a DFD for the dental surgery and ask the learners what they found difficult. Discuss how the learners could start to develop their own DFDs.

5 Learner guidance This two-stage activity is designed to help you understand and construct Data Flow Diagrams This activity is about constructing Data Flow Diagrams (DFDs). The activity consists of two stages. The first stage is a role play of a scenario based on a dental practice. You might be asked to play the role of a patient, the receptionist or the dentist. You will be given briefing notes to tell you who they are and what you need to do. If you are not part of the role play you will be part of a small group whose job is to observe and capture the entities, data flows, processes and data stores. Discuss issues with your group members and record your findings on flip charts or whiteboards. For the second stage you will be assigned to a small group and be given cards with entities, data stores, processes and data flow arrows from which you are to construct a Data Flow Diagram for the dental practice system. Learning objectives This session aims to get you to understand how to construct DFDs and to understand the symbols used in one notation, Standard Systems Analysis and Design Method (SSADM). At the end of this session you will be able to: recognise and use the symbols required to construct a Data Flow Diagram create a Data Flow Diagram for a given system. Resources Role play material. Cards used to create a DFD of the dental practice. Learner guidance notes. Flip charts or whiteboards and pens.

6 Your task is to construct a DFD for a dental practice using cards with the data flow elements Stage 1 - Role play 1. If you have been chosen to play one of the roles (patient, receptionist or dentist) you will be given a card explaining your role. Do your best to put yourself in the role and enjoy taking part. 2. If you are not playing a role, you will be a member of a small group whose job it is to record what you see going on in the role play and to identify and write down the entities, processes, data stores and data flows as the role play proceeds. You should select one of the group to do the writing and record the entities, processes, data stores and data flows on a flip chart or whiteboard. You will need to discuss what to write with the other members of the group. 3. At the end of the role play your group will be asked to briefly explain what you have recorded. You will need to select a member of your group to speak on your behalf. Stage 2 - Creating a DFD 1. For this stage your teacher or trainer will form new groups of three or four. Your task, as a group, is to create a DFD for the dental practice system using cards with the given entities, data stores, data flows and processes. You will need to discuss how to do this with your fellow group members. 2. At the end of this stage, you will be asked what problems you met.