Posted by: reto2 | February 7, 2009

Week 12

The most difficult assessment complete in this course was assignment 2, because it was a large assignment.

At the beginning to design the ERD was a difficult task to do, I as confused with DFD because I was approaching this task as I would approach DFD; it took some research and academic assay it become clear. Design the ERD is a very important task and on completion it was easy to visualize the entities involved in the new system.

Moreover the feeling of doing something that looks so complicated is good I actually enjoy doing it. (Hope the ERD in my assignment is OK ).

 In my opinion it will be good to maintain ERD as a task in next year’s assignment. In the other hand I  didn’t  mind  to do the academic essay, but  the demand of 2500 words  for that assignment was to much, if I have to change something I would reduce it to 1500 words.

 In this course I learn many things, but I enjoy doing the DFD and the ERD. What’s more I learn that there is not small or insignificant task involves in developing a new system; you have to pay attention to all of those tasks since all of them are vital for the new system.

 Also I learn the importance of each stage involved in developing a new system, specially now with all the new technologies available, it is very important to keep up to date with all this news tendencies to be able to develop systems that will keep a company’s succeeding, efficiently  and productive. Moreover I learn the new tendencies in developing new systems for organizations and what is available in the market today.

 In the near future I would like to work as a system analyst and be involved in developing new projects. And this course is certainly the right one to be studying to achieve my goal. Also I would like to work as a programmer because it is amazing how you can create so many things with the right tools and knowledge.

Posted by: reto2 | February 1, 2009

WEEK 10

Maintenance Activities

 Computer system must be maintained carefully by trained professional. Another important issue to be aware of is that any maintenance work that could affect the system must be performed first in the test environment, and then migrated to the operational system. There are four type of maintenance task performed to fix errors and they are: corrective maintenance perform to fix errors, Adaptive maintenance add new capabilities and enhancement, perfective maintenance improves efficiency and preventive maintenance reduce the possibilities of future system failure.

 Corrective Maintenance: this maintenance diagnoses and corrects errors in an operational system, In addition to errors in the original version of the system. Corrective maintenance often is needed to resolve issue created by previous maintenance changes.

Adaptive Maintenance: adds a new feature or capability to an operational system and makes the system easier to use.  This type of maintenance usually arises from business environment change such as new products or services, new manufacturing technology..

Perfective Maintenance: involves changing an operational system to make it more efficient, reliable, or maintainable. Usually perfective maintenance is cost effective during the middle of the system’s operational life. Early in system operation, perfective maintenance usually is not needed. Later perfective maintenance might be necessary, but have a high cost.

Analyst often use a technique called software reengineering, this uses analytical techniques to identify potential quality and performance improvements in an information system.

Preventive Maintenance: this requires analysis of areas where trouble is likely to occur. This maintenance often results in increased user satisfaction, decreased down time, and reduces total cost of ownership. 

 The Bowen high school student record system (BHSSRS) is a new implemented system therefore the only type of maintenance that will be perform will be the corrective maintenance.  However, I see preventive maintenance as a very important strategy for implemented systems, therefore it should be consider as an option to perform in this system. This will help to prevent trouble to occurs in any area of the system or to increased user satisfaction or else decreased down time. The other type of maintenance describe before are not necessarily at this stage of this new system.

Posted by: reto2 | January 26, 2009

Week 9

System changeover for the Bowen high school student’s record system (BHSSRS)

 System changeover is the process of changing the old information system for the new one. This could be done using 4 different methods.

 Direct Cutover: this method deals with cutting the old system and put the new one in place. This is similar to throwing a switch that instantly changes over from the old system to the new one.  This is the less expensive changeover method, because the IT group have to operate and maintain only one system at a time. Nevertheless, cost in this change over is low the risk is high, firstly because some difficult can arise when the system goes into operation period. Secondly detecting small errors is more difficult with this change over method because users can’t verify current output by comparing it to output from the old system. Finally and the most important reason in my opinion is that major errors can cause a system process to terminate abnormally, and it this happens the system can’t be reverts to the old system as a backup option.

 Besides this, very important conditions to consider in choosing this method are, if the operating environment cannot support both the old and the new system or if the old system and the new one are incompatible.

 In the case of the BHSRSS this approach could be a extreme option to use and also is a  high risk option because represent to place a system into a full operation period and deal with the possibility of   operational problems. In addition to this the old system won’t be a backup to run in case something wrong happens with the new one. About the comparison of the output information of the new system with the old one is not a relevant issue because of the redundancy and inconsistency of the information from the old system.

 Parallel Operation: this method requires that the old and new system operates simutaneasly for a specific period. The output data from both systems are compared for that period until the IT group and the management are satisfied with the operation and result of the new system, afterwards the use of the old system is finished. The risk with using this method is low, because both systems are functioning at the same time and the outputs for both system are easy to compared and verify.  Another serious issue is that if anything goes wrong with the new system, the company can use the old system as a backup system until the change on the new system are made.This changeover method is the most expensive of all the 4 method because the company have to operates and maintain both entire systems at the same time. In addition running both systems may cause trouble on the operating environment and as a result processing delays. Parallel operation method is not practical if the old and new system are technically incompatible or if the operation environment can not support both system. Also is inappropriate if when the 2 system perform different functions or if the new system involves a new method of business operations. 

 This approach is not recommended for the BHSRSS because of the cost and also because the output information generates from the old system is inconsistent and redundant according with the real information. 

 Pilot Operation: this approach involves implementing the complete system at a selected location of the company.  With this method the old system continues to operate in the entire organisation including the pilot site. After the system prove successful at the pilot site. It is implemented in the rest of the company, usually using a direct cutover method. This method is a combination of the parallel operation and direct cutover. The risk of system failure with this method in comparison  with the direct cutover  is reduce because it is confine in within an specific area of the company called pilot site. Also to operate both systems in a pilot site result less expensive than a parallel operation for the entire company furthermore the changeover period can be much shorter if the system proves successful at the pilot site.

 This Approach will be in my opinion the best approach to use to implement the new information system in the Bowen High, implement a pilot maybe in the student registration  and see how it work and after a period of  running and working good of the new system concluded the use of the old one. Using the direct cutover.

 Phase Operation:  this method allows implement the new system in stage of modules. Also combines parallel operation and direct changeover to reduce risk and cost.  The cost and risk factor are reducing because it works with only one part on the system at the time. This approach is not possible if the system cannot be separate easily into logical modules or segments. Also if the system involves a large number of separate phases, phased operation can cost more than a pilot approach.   

This approach is also a choice to use to  implement the new system at the Bowen high  because the whole system can be divide in stages or modules  at the same time is not the best choice to  recommend to use for this information system because could happens that the system works very good for the borrow books module but that doesn’t mean that  it will be the same for the student enrolment.

Posted by: reto2 | January 12, 2009

Week 8

Dennis, A., Wixon, B  2003, System Analysis & Design, 2nd edn, John wiley & sons Inc, New York.

Shelly, G., Cashman, T., Rosenblatt, H. 2008, System Analysis and Design, 7th  edn, Thomson Course Technology, Boston. 

 Kendal, K. & Kendal J., 2005, System analysis & Design, 6th edn, Rutgers University-School of Business, New Jersey.

Technology Evaluation Centres, TEC ‘Five key point for continuous improvement in the life-cycle of processes‘ 2008 http://whitepapers.technologyevaluation.com

 Process Model: Describes the activities that people do in an organisation and can be used to describe the existing system and the propose system. The most common tool use for this is the Data Flow Diagram or DFD as I am going to refers from now on. Process model is a formal way of representing how a business system operates. It shows how the activities perform and the data that flow or moves between them. ‘Although the name DFD implies a focus on data this is not the case. The focus in mainly on the process or activities that are performed’    (Dennis,  & Wixom 2003, p.168

Data Flow Diagram (DFD):   This Drawing technique represent how data moves through an information system but doesn’t show what programs logic or processing steps. A DFD provides a logical model showing what the system does but not show how it does it.  (Cashman 2008, p.152)

Data Model: Describes the data that moves  through the business process in an organization, during the analysis phase the data model presents the logical organisation of data, but later in during the design phase the data model is change to reflect exactly how the data will be stored, in database and files. (Dennis, & Wixom 2003, p.203)

 One of the main reasons to created process model is to represent how the business system will operate, additionally one of the most commonly used techniques of representing model data are the Entity Relation Diagram (ERD). (Dennis, & Wixom 2003, p.204)

Entity Relation Diagram ERD: ‘is a picture that shows the information that is created, stored, and use by a business system.’  Usually System analyst read and ERD to find out the individual pieces of information and how they are organize and related top each other (Dennis, & Wixom 2003, p.205)

Data and Process Modeling

Both Involves three main tools: Data flow diagram, a data dictionary, and process description.

 A range of diverse tools can be considered for modelling, from basic Office tools to more specialized software such as Visio or tools like Aris and Adonis that are specially design for use at this stage.

Based on the available knowledge result from modelled and analysed the process, it will be easy to decide what needs to be changed to make improvements in the process to be. Technology Evaluation Centres, TEC ‘Five key point for continuous improvement in the life-cycle of processes‘ 2008

 Additionally both data and process model are Graphical techniques use by system analyst to develop graphical models to show how the system transforms data in to useful information (Kendal, K & Kendal, J 2005, p.192,193)

 

 

 

 

 

 

 

 

  

Posted by: reto2 | December 28, 2008

Week 7

 Process Modeling  Vs  Data Modeling 

Differences:

Process Model: Is a formal way of of representing how a business system operates. It illustrates the processes or activities that are performed and how data moves  around them. The most common technique to process model is the Data Flow Diagram (DFD) 

A DFD shows how data moves through an information system. Also provide a logical model that shows what the system does, but not how it does it. 

Data Modeling:  Data modeling describe the data that flows through the business process in an organization.  the date model presents the logical organisation of data without indication how the data are stored, created, or manipulated.  during the analysis phase the analyst use Entity Relation Diagram (ERD) as one of the most common data modeling technique  used in industry. 

A Data Model is a formal way of representing the data that are used and created by a business system, it illustrated people, places, or things about which information is capture and how they are related to each  other.

The Data Model is drawn using an iterative process in which the model becomes more detailed and less conceptual over time

Similarities:

System Analyst develop graphical models to show how the system transforms data in to a useful information, during the data modeling and process modeling system analyst use ERD and DFD to show this transformation.

The end product of data and process modeling is a logical model that will support business operation and users needs.

Data and Process modeling involves three main tools: Data flow diagram, a data dictionary, and process description.

Posted by: reto2 | December 21, 2008

Week 5

Data Dictionary:  

is a central storehouse of information about the system’s data. An  sytem analys uses to collect, document, and organize specific facts about the system inluding the contents of data flow, dta stores,entities and processes. Also they define and describes all data elements and meaningful combinations of data elements.

Data Dictionary for a rental video process

Example

·         Process name: Rent videos

 ·         Process number:  1

 

·         Purpose: This process is in charge of keeping track of the videos rented by the customers. And customers details subscription.

 

·         Input data flows:

1.      Customer ID

2.      Family name

3.      Given Name

4.      Gender

5.      DOB

6.      Address

7.      Home Phone

8.      Mobile

9.      Email Address

10.  Video_code

11.  Video_Name

12.  Video_category

13.  Rental_type

14.  Rent_Date

15.  Rent_Due_Date

16.  Video_Rental_Payment

 

·         Output data flows

1.      Videos rented  list

2.      Customers list

3.      Videos report.

4.      Customers report

 

·         Process description: This process registers all the new subscription request by new customers also keeps track of all videos rented by them and their personal details.  

 

·         Notes: In this process the customer register an account with the video rental shop at the same time this process keep records of all the videos rented by the customers.

Posted by: reto2 | December 12, 2008

Week 4

video-rental

Data Flow Diagrams: During the system  Analysis phase  a visual model of the       information is neccesary. This can be done usin a set of data flow diagrams. 

Data flow diagram (DFD) shows how data moves through an information system but does not shows program logic or procesisng steps. a set of DFD provides a logical model that shows what the system does, not how it does it. 

DFD use four basic symbols thta represent processes, data flows, data stores, a nd  entities.

Constructing a DFD

Contex Diagram : The firs step to constructing a DFD is to draw a contex diagram, this is  a top level view of an information system that shows the system boundaries and scope.

Diagram 0: This zoom in on a the system and shows major internal processes, data flow , and data stores. Diagram 0 also repeats the entities and data flow thta appear in the contex diagram. when you expand the contex diagram into a DFD 0, you must retain all the conections thta flow into and out of process 0.

The files attached are examples of  a contex diagram and  “0″ diagram 

“0″ DIAGRAM

video-rental-diagram-0context-diagram

CONTEXT DIAGRAM

 

 

Posted by: reto2 | December 6, 2008

STRATEGIC PLANNING

STRATEGIC PLANNING

  Companies develop and maintain IT systems to support their current and future business operation. Most successful IT managers engage in long-range planning, even as they handle day- to-day maintenance and support.

Strategic planningis the process of identifying long-term organizational goals, strategic, and resources. It looks beyond day-to-day Activities and focuses on a horizon that is 3,5, or even 10 years in the future.

Now this  is the question, Why system Analyst  need to know strategic planning ?  System Analyst should focus on the  large, strategic role of IT as they carry out  their day-to-day responsibilities . During strategic planning top managers ask a series of questions that is called a SWOT Analysis because it examine a company’s Strengths(S), weaknesses(W), opportunities(O), and Threats(T), Each question may lead to an IT related issue; which in turn requires more review, analysis, and planning.

A SWOT analysis contributes to the strategic planning process by identifying technical, human, and financial resources.

From Strategic planning to Business Results

A company develops a mission statement based on the firm’s purpose, vision, and values. The mission statement is the foundation for the company’s major goals, shorter-term objectives and day-to-day business operations. Critical success factors are vital objectives that must be achieved  fro the enterprise to  fulfill its mission,  and critical business issues are the key problems, opportunities, and constraints that affect  and shape the firm’s decisions just like a SWOT analysis.

Posted by: reto2 | December 4, 2008

System Development Methods

There are various methods for developing information system, but the most popular alternatives are Structured Analysis,  and and Object-orientated-analysis (O-O).

Structured analysis is a traditional system development techniques that is time -tested and easy to understand. This methods uses a series of phases  called system development life cyclo (SDLC), to plant analyze, design,implement and support an information system. This methods  is focus in on processes that transform data  into useful information, in this methods  data and processes are treats as separated components. The  SDLC  Model usually includes five steps: System Planning, system Analysis, system design, system implementation, and system operation, support and security.

Object Orientated Analysis,  This methods combine data and the processes that act on the data into things called objects.  Object orientated is use to model real world business processes and operations. The result is a set software objects that represent actual people, things, transactions, and events; using a programing language a programmer then writes the code that creates the objects. 

The bottom line is that the system analyst should understand the pros and cons of any approach before selecting a development method for a specific project.

The important of project management Regardless of the development strategy, people,task,timetable ans expenses must be managed effectively,  Project Management, is the process of planning, scheduling, monitoring, controlling, and reporting upon the development of an information system.

Posted by: reto2 | December 4, 2008

Information Technology(IT) Department

The IT Department develops and maintains a company’s information systems. the IT structure varies among companies.  The following  information shows a typical IT Roles  in a company that has networked PCs.

Application Development: Group of system Analyst and Programmer who handle information system design, development and implementation.

Systems Support and Security: implements and monitors physical and electronic security hardware, software and procedures. They provide vital protection and maintenance’s services for system hardware and software including enterprise computing systems, networks, transaction processing systems and corporate IT infrastructure.

User Support:  is also called help desk or information center, they provide users with technical information, training and productivity support.

Database Administrator:  involves Database design, management, security, backup and user access.

Network Administration: includes hardware and software maintenance, support, and security. in addition to controlling user access, network, administrators install, configure manage,monitor and maintain network applications.

Web Support: Is a vital technical support function, often calls WEBMASTERS, support company’s Internet and Intranet operations, involves web page design and construction, monitoring traffic, managing hardware and software and linking Web Base applications to the company’s existing information systems.

The System Analyst Position:The system Analyst investigate, analyses design, develops, installs, evaluates, and maintains a company’s information sytems. they constantly interacts with users and managers within and outside the company to perform these roles. The system Analyst’s job overlaps business and technical issues. Analysts help translate business requirement into IT projects. A system analyst plans projects,develops schedules and estimates cost. To keep managers and users informed.

Older Posts »

Categories