Saturday, December 20, 2008

System Analysis And Design (Reflection)

Chapter 1
In this chapter focus and discuss how a system relates to a software or the differences between them, also how the development team response to the problem that the customer demand for his/her system. So if we relate a system to a software; a system is a step by step instruction or procedure in order to build an output while a software is tool to implement a system. So as i define system with software; system comes first, the process in which it take a long period of time to gather data and analyze those data gathered. I say that it take a long period of time because it concerned with the efficiency and effectiveness that the customer demand for his/her specific system. Meaning to say in order for the efficiency and effectiveness of such system. They must pursue to take some action regarding the problem speakted to happened. And break those problems into small block of pieces to be able to know or to represent a particular weakness of the said system. If all this things might approved by the customer demand the cycle of doing the analysis with a particular system is then stop. And now the cycle of doing the software for implementation and representation according to what thus the development team have analyze in his/her system is then start. And then verify that the complete system work as what the customer wants. But it doesn't stop in this cycle; what if the software is done and you will deliver it to the customer and what if the customer demand again and do some additions to his/her system. Then the maintenance team take the possible additions and fixes the system if it encounter fault after it have been delivered or what i have said some additional information in his/her system. The cycle of doing the system never stop because the customer's seem nowadays that the evolution of doing a system,software becomes the competition of other customer's.

Chapter 2

In this chapter discuss the software life-cycle or what we called software development process and the different kind of software life-cycle models also the process of doing a software. So before the following models is discuss first we define a process; a process is a step involving activities, constraints and resources that produces an intended output of some kind. The different kind of software-life cycle model are Waterfall models, V-models,prototyping Models, Phase development Models, and the Spiral Models.

In Waterfall model one development stages should completed first before the next stage begins. The system analyst never stop until it completely done every one stages. and every stages take system testing that includes validation and verification. In validation, it ensures that the system was implemented all of the requirements and in verification ensures that each function works correctly. In V-Model, the requirement analysis works with the customer and captured all possible problems that might happened, and breaking those problems into small block of pieces of what the customer wants into discrete requirements. Then designer, design the speakted outcome of the customer's demand for his/her system. And at center of this V model is the programmer who implement the software through codes. The the tester who catch the possible faults and Maintenance who fixes the system if it encounter faults after it has been delivered. This models the validation and verification of requirements become the problem of the said model because the requirement analyst and the maintenance team quarrel about the validation of requirements and also this happen between the designer and the tester and all of the said validation and verification of requirements will take by the programmer and do some implementation according to what will considered in the team.In Prototyping models every stages of developments represent an expected output base on the customer demand.
In Phase Development Models there are two way of doing do. First, the incrementation and second the iteration. In incrementation every subsystem will release if it will function. the a customer's demand again for another function to be done so this model will add again and again until it is fully done. The process take a long period of time because adding again and again another function in order to produce fully will make it so long. In iteration, At the very beginning of the development team produce a small function on their system, they will release it immediately. And if there are changes about the functionality of each subsystem they do again and release until it was done. So there is no differences between this two way for phased development but they only offer in style or paradigm on the concept of approaching the process of doing the software.In Spiral Model it considered as same as what the incrementation is done. The style and process of doing is the same but the concept of doing so are different in term of their approach.

The Life cycle of software development take haft of System Analysis And Design and half that focus on the software maintenance. The member of development team are the requirement analyst,designer, programmer,tester, customer, trainer,librarian,maintenance.
Requirement Analyst whi is work with the customer, finding all possible problem and breaking those problem into simple one. Designer who represent and generates a system-level- of description. Programmer who implement the requirement through codes. tester who catch faults that the programmer may have overlooked. customer who verify that the complete system works. Trainer who show and teach the users. Maintenance team who fixes the system after it will delivered. Librarian who prepares and store document during the life of a system.

Chapter 3

In this chapter discuss planning and managing a project. Planning a project take several steps and each steps involve activities to considered. The several steps are the tracking progress,work breakdown and activity graphs,estimated completion,effort estimation and risk management. in tracking progress, project schedule is one of the steps that the development team portrays the interactions among those activities and estimate the time that each task or activity will take. In this steps describes the software development cycle for a particular project. Deliverable is a steps that the customer expect to see during project development or items that the customer demands. Activity a steps in which a part of project that take a long period of time to accomplished. Milestones is a completion of an activity a particular points of time.
In work breakdown and activity graphs,it involved precursor,duration,due date, end-points, activity graphs. Precursor is a set of event that must occur before the activity can begin; Allow and describe the activity to begin. Duration is a length of time needed to complete the activity. Due date the date by which the activity must be completed frequently determined the contractual deadlines. End-points is the milestone deliverable. Activity graph, the nodes of graphs the the project milestone and the line that represent the activities involved.
In estimating completion explain that the minimum amount of time it will take to complete the project given the length of time as a based a time needed to complete the activity. This involved deadlines,schedules,or estimated amount of time required an activity to be completed. It also show how the gantt chart helps the project manager to understand which activity will performed and also show what the proper deadline that the activity must be completed.
in effort estimation; in this phased tells the technique and judgment according of how the project activity is done. It involved verification and make some educated guess about the effort needed to build an entire system. And also tackles possible risk happened in such project activity. Risk by the way is an unwanted event that has negative consequences. If this risk will be ignored this may caused loss of associated events, there is a possibility that like hood event will also occurred, so in order to avoid risk you must check the degree of which you change the outcome in order to reduce and eliminate a risk.

Chapter 4

In this chapter involve the discussion of System Requirement and the two categories of this requirements. System Requirement are all capabilities and constraints that the new system must meet. Generally it divide into two categories: the functional and non functional. The functional requirements are activities that the system must perform.. It take all the important detailed that the software must do.. and non functional are those thing thus not involve function..meaning to say it is only a flowering of the software..

Chapter 5

In this chapter discuss An abstraction; a view or representation os an entity that includes only the attributes of significance in a particular context. Abstraction allows one to collect instances of entities into groups in which their common attributed need not be considered these common attributes are abstracted away. Within the groups, only the attributes that distinguish the individual elements need be considered. This results in significance simplification of the elements in the group.Less abstract view of these entities may be considered when it is necessary to see a higher level of detail. Abstraction is a weapon again complexity of programming; It purpose is to simplify the programming process. It is a effective weapon because it allows programmers to focus an essential attributes and ignores subordinate attributes.
Inheritance offers a solution to both the modification problem posed by abstract data type reuse and the program organization problem. If a new abstract data type can inherit the data and functionality of some existing type, and is also allowed to modify some of those entities and add new entities, reuse is greatly facilitated without requiring changes to the reused abstract data type. Inheritance inherit entities from its parent class, a derives class can add new entitie4d and modify inherited methods. A modified method has the same name and often the same protocol, The new method is to be override to produce an operation that is specific for object of the derived class but is not appropriate for object of the parent class.
Object an instance of an abstract data type, one of the motivation for the abstraction against complexity, is making large and/or complicated programs more manageable.
Also it tackles about traditional approach and Object-Oriented approach. In traditional approach discussed ways of how you manipulate implementation by using hand to hand implementation. Hand to hand implement action because the way you analyze the program seem difficult in a way that you and the flow of the computer must relates to each other in order to make efficient and effective a program is. In traditional approach involved entity relational diagram (ERD) will tell the relation between the customer and the project team, It will test first how the flow of a system executed while in Object Oriented Approach it uses objects that represent a particular functions it mush easy compare with the traditional because less effort is applied in this approach.

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