Week 12

 

1. What was the most difficult assessment item you completed in COIS20025 this term (not counting the examination which is not until the examination period)?

One of the most difficult assessment item was the academic assay in part B of the assignment to ‘Compare and contrast the traditional and object approaches to system development’.

2. What was difficult about it and how would you suggest it could be improved?

The most difficult part about the academic essay was that there were not enough resources online and in electronic databases and journals. I suggest that the topics like this should be discussed in the tutorial prior to doing the assignment.

3. Name three (3) things you learnt this term in COIS20025.

I have learnt how to

1. Create the Entity -Relationship Model

2. Normalization

3. Data flow diagrams

4. What career are you working towards?

We are working towards building a career in information systems as a systems analyst or an information system developer.

5. How will you be able to use the knowledge and skills learnt in this course in your future career?

I think the knowledge and skills learnt in this course can help us a lot in the future to work with the entity relationship models and the data flow diagrams and the knowledge gained by working on assignments would be of great help in the future.

Week 10

Discuss four possible approaches for changing from one information system to another and explaining the implications of using each of these approaches at Health Centre’s to change from the existing manual system to the new CHIS including discussion of the benefits and problems associated with each approach.

There are four different approaches with different risks and the cost factors.

1 Direct changeover : In this changeover method the changeover is immediate from the old system to the new system. In this system the operating costs will be less as only one system will be in operation at a time. However, there is also a disadvantage as there will not be a backup. There is a chance that the Health centre may not support both the systems, then the best option for the health centre’s is to use this method.

2 Parallel Operation : In this changeover method, both the old and the new system operates fully  at a particular time. In this method the data is entered in both the systems and is tested for consistency. If the health centres adopt this method then there is least risk as the results can be compared and a back up is created. However, this method is relatively as both the systems operates for a full period.

 3 Pilot Operation : In this changeover method, the new system is installed in a single department in an organization and the rest of the organization continues to use the old system. In this changeover method the cost is relatively moderate as the new system is tested only at one particular site and the risk involved is also less.

4 Phased changeover- In this the changeover method, the new system is implemented in different stages or modules across the Health Centres. In this system  a part of the new system is installed at the health centres for testing and the cost involved in this method is also less as the new system is implemented in stages and the risk involved is also less.

 

Week 9

 

Four possible approaches for changing from one information system to another. These approaches can be helpful for the  Health Centres to change from the existing manual system to the new Child Health information System (CHIS).

Direct Cutover : This  approach needs the system to change from the old system to the new system when the new system becomes operational. However,  this is the least expensive approach method because the IT department has to operate and maintain only one system at a time. This is considered as the risky method, because  even after testing and training some problems may arise when the new system becomes operational.

Companies often choose this method to implement commercial software packages because they feel that the commercial packages has less risk of total system failure. Most of the times, direct cutover is only used by the organizations for non critical situations.

 

Parallel Operation :  This method requires that both the old and the new information systems operates completely for the specified period. In this method, data is used as input for both the systems and the output is generated by the new system when compared with the output form the old system.  The main advantage of this operation is that it involves lower risk. If the new system doesn’t work  the old system can be used as a back-up until the changes are made to the new system.

Parallel operation does have some disadvantages and it’s also a costly changeover method. Because in this method, both the old and the new system will be in full operation and the company has to pay for both the systems during the parallel period.  This system is not practical if the operating system cannot support both the systems .

 

Pilot Operation :  This method requires implementing the complete new system at a selected location of the company. In this method the new system is installed only in one specific department of an organization and is called a pilot site. During this testing period the old system continues to work in other departments except the one where the new system is installed. After the new system is proved successful, it is installed in other departments. Therefore, pilot operation is a combination of parallel operation and direct cut-over methods.

By implementing the new system this way, reduces the risk of system failure and is also less expensive than a parallel operation.

 

Phased Operation : This changeover method allows us to implement the new system in different stages or modules. For example, instead of implementing a new manufacturing system at once we can install the materials management subsystem and then the production control subsystem and then the job cost subsystem. We can implement any of the subsystems by using any of the changeover methods.

However, systems analysts sometimes confuse phased and pilot operation methods. These two methods combine both direct cutover and the parallel operation methods to reduce the risks and costs. One of the advantages of this approach is that the risk of the errors or failures is limited to the implemented module.  If a new production control subsystem fails  to operate then it may not affect the new subsystem or the existing control subsystem.

 This system is less expensive than the full parallel operation because it requires that we have to work with only one part of the system at a time.

 

Recommendations  for CHIS : It is recommended that the phased operation changeover method must be used for the CHIS as this will allow the new system to be implemented in different sub-stages  and it is also less expensive than the changeover methods  as it is required that we have to work with only one part of the system at a time.

Week 8

Textbooks, journal articles and websites that define traditional and object-oriented approaches to information systems development and describe their similarities and differences.

Rob, MA 2006, ‘Dilemma  between the  Structured  and Object-Oriented Approaches  to Systems  Analysis  and  Design’,  The Journal of Computer Information Systems, Vol. 46, Iss. 3; pp. 32.

In recent years, there has been a surge of interest in adapting object-oriented (OO) concepts, UML, and Unified Process of system development in the Systems Analysis and Design texts. However, there is a question of how to best fit these concepts with the existing coherent discussion of structured approach. This paper addresses some of the intricacies of OO concepts such as complexity of diagrams and models, weak links between phases, and lack of support for designing system components. We would like to recommend that there should be a separate text for the OO methodology and it should not present various OO models according to the phases of the traditional structured approach, rather it should focus on the evolution of the models leading to the design of the system components. Furthermore, there should be a standard set of models for the OO methodology as well as a clear definition of steps as an analyst moves from one set of models to the next.

 

 

Wieringa, R 1998, ACM Computing Surveys, Volume 30 ,  Issue 4, pp. 459 – 527

http://portal.acm.org/citation.cfm?id=299917.299919 This article surveys techniques used in structured and object-oriented software specification methods. The techniques are classified as techniques for the specification of external interaction and internal decomposition. The external specification techniques are further subdivided into techniques for the specification of functions, behavior, and communication. After surveying the techniques, we summarize the way they are used in structured and object-oriented methods and indicate ways in which they can be combined. This article ends with a plea for simplicity in diagram techniques and for the use of formal semantics to define these techniques. The appendices show how the reviewed techniques are used in 6 structured and 19 object-oriented specification methods.   Qian, H , Fernandez, EB 1995, “A combined functional and object-oriented approach to software design,”  First IEEE International Conference on Engineering of Complex Computer Systems, pp 167. http://csdl2.computer.org/persagen/DLAbsToc.jsp?resourcePath=/dl/proceedings/&toc=comp/proceedings/iceccs/1995/7123/00/7123toc.xml&DOI=10.1109/ICECCS.1995.479323 Large and complex software systems contain a variety of entities (objects) and a complex control system (transformation function). The pure object-oriented design and structured design approaches concentrate on either objects or the transformation function separately. As such they may not be adequate in isolation, to deal with the design of complex systems. Therefore, it makes sense to study their combination. We propose a combined functional and object-oriented design approach (CFOOD) based on the extended object-oriented design method proposed by P. Jalote (1989, 1991). The CFOOD approach makes full use of the object-oriented design and structured design techniques combining the object view and the functional view to provide a more complete view of a system. We demonstrate the use of our approach by a design example of a hospital patient monitoring system.

 

Week 7

Name one way that the traditional and object-oriented approaches to information systems development are similar. Explain how they are similar.

 Traditional and object-oriented approaches are  similar in the systems implementation phase when the new system is constructed.  Whether the developers used structured analysis or object-oriented methods, the procedure is the same-programs are written, tested and documented and then the  system is installed. If the system was purchased as a package , system analysts configure the software and perform any necessary modifications. The objective of the system implementation phase is to deliver a completely functioning and documented information system.

At the conclusion of this phase, the system will be ready for use. Final preparations include converting data to the new system’s files, training users, and performing the actual transition to the new system. The systems implementation phase also includes an assessment, called a systems evaluation, to determine whether the system operates properly and if costs and benefits are within expectations.

Name one way that the traditional and object-oriented approaches to information systems development are different. Explain how they are different.

When implementing a structured design, a structure chart is used to describe the interaction between program modules, however when implementing an object-oriented design, relationships between objects already exist. Because object interaction is defined during the object-oriented analysis process , the application’s structure is represented by the object model itself. Because objects contain both data and program logic, called methods. Individual object instances belong to classes of objects with similar characteristics. The relationship and interaction among classes are described using a class diagram. A class diagram includes the class attributes, which describes the characteristics of objects in the class, and methods , which represent program logic.

When a programmer translates an object-oriented design into an application , he analyzes the classes, attributes, methods, and messages that are documented in the object model. During this process, the programmer makes necessary revision and updates to class diagrams, sequence diagrams, state transition diagrams and activity diagrams.

 

 

Week 5

Develop a Data Dictionary entry for a process from the diagram 0 DFD for borrowing a DVD from Video Rental Shop. Using the following heading :

Process name, Process number, Purpose, Input Data Flows, Output Data Flows, Process Description, Notes.

 

1.

       Process name        

       Verify membership                  

       Process number                      

       01

       Purpose

Verify membership information of the customer.

       Input data flow                       

      Membership application.

      Out put data flow                    

       Approval

       Process description               

 To verify membership application and then approve the membership if the applications are appropriate.

 

 

2.

Process name                           

Process request

       Process number                      

       02

      Purpose  

      Process customer’s DVD Request and grant the dvd’s to the customer.

Input data flow            

Receive DVD request.

      Out put data flow        

      Approve DVD request.

      Process description    

      Proceed information about customer’s dvd orders.

 

3.

      Process name                           

      Payment process

      Process number                       

     03

      Purpose              

     To verify and process customer’s payments.

      Input data flow

      Receive payment.

      Out put data flow                    

       Issue payment receipt.

      Process description                      

      To verify the customer’s payment details and ro keep track of the payment system.

Week 4

Create a context DFD and Diagram 0 DFD of the processes you need to complete when borrowing a DVD from a video rental shop.

Context diagram for a DVD rental system.

 

Diagram 0 DFD for DVD rental system

Week 3

What is the traditional approach to systems development ?

What is the object-oriented approach to systems development?

 What textbooks, journals and/or websites might be useful to search for articles about Comparing and contrasting the traditional and object-oriented approaches to systems development?  

To answer these type of questions we can make use of the fact finding techniques like document review, observation, questionnaires and surveys, sampling and research.

FACT FINDING : Fact requires that we need to indentify all the required information. We can start by finding out the business functions that are supported by the current system and strategic objectives and business requirements that must be supported by the new system.

Document Review : This can help us understand how the current system is supposed to work. However, the system documentation can sometimes be out of date and it can be changed or discontinued and the documentation procedures are also modified and removed periodically. We can also use copies of the actual forms and the documents that are used and review blank copies of forms as well as the copies of the completed forms and if the system uses a software package we can review the documentation for that software.

Observation : To observe the current operating procedures is another fact-finding technique. By monitoring the system in action will give a better understanding of the system procedures. Through personal observation allows us to verify statements made in interviews and determine whether procedures operates as they are designed and with observation it can be discovered that the system documentation and the interview statements are accurate. Personal observations can also provide important advantages as the development continues. Observations also provide the knowledge required to test or install future changes and can help create relationships with the users that will work with the new system.

Questionnaires and Surveys : A questionnaire, also called a survey is a survey that includes a number of questions that can be sent to many people. Questionnaires can also be used to get information about different topics, including workloads, reports received , volumes of transactions handled , job duties, difficulties and opinions of how the job can be performed more efficiently. A questionnaire starts with a heading, title, statement of purpose, name and telephone number of the concerned person, deadline and the date of completion, and how and where to return the form. The heading is generally followed by general instructions that provide clear guidance on how the questions can be answered. Headings are also used to mention each section of the survey and also includes the instructions when the questions or the response changes. A questionnaire will generally end with a conclusion to thanks the participants and reminds them how to return the form

Sampling : Sampling is a process of collecting examples of actual documents. The samples include records, reports, operational logs, data entry documents, complaint summaries, work requests and various type of forms. This technique includes systematic sampling, stratified sampling and random sampling. We can also consider sampling while using interviews or questionnaires. Instead of interviewing or sending a questionnaire to the entire group, we can use a sample of participants.

Research : Research is another fact finding technique. It includes Internet, IT magazines and books to get information, technical material, and news about the industry trends and developments.

Week 2

What are the current problems with the Child Health Information System?

The current problems faced by the Child Health Information Systems is that there is no centralized system to gather and store health data from children which is required  by the Department of health and some donor organizations like the  World Health Organisation (WHO). The major problems faced by the Child Health Information Systems are  there is no exact information about the number of children who have been vaccinated and the vaccines that they have been given as there has been a boost in population and decline in budget, and there is no proper system to keep track of the children’s weight so its difficult for the health department to provide treatment to the children who are underweight, and its also difficult for them to maintain records of the diseases that the children had in the past.  

What information do you need to find out about the Child Health Information System to develop a detailed understanding of the current system?

 The information required to develop an understanding of the  the Child Health Information system is as follows

• The details of the health centre information like the health centre name, contact information like the fax and the telephone number and the number of people being served by the health centre.
• Child information like the names of the children, identity number, age, gender and the information about the school attended by the children.
• Information about the type of vaccines used and provided to the children on a particular visit.
• Medical visit information like the child weight and the disease the child has been treated for.
• Type of diseases that are most commonly found in these children.

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