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Jumat, 27 Maret 2009

fourth Quiz

Requirement Analysis



INITIAL INVESTIGATION

System Investigation Concepts

Problem is gap between purpose of system and real condition of system, with any word, why system fail to reach their purpose of system that have definite before. to know everything that cause system fail analys better have to investigation before taking something to do for repair system. With investigation, an analys will more understand the problem and discussion

Many repair in detecting a problem may not real or not solved. It can be happen because :

a. purpose are too ideal

b. system can’t developed

c. system measuring not accurate

d. statement goal is dated

e. the gap between the ideal and the current system is temporary and will decrease given patience

in stage of problem solving, better to have study with :

  1. describe system condition that have pass with detailed investigation activity
  2. get the ideal system consensus
  3. developing some alternative to decrease gap between ideal system and pass system
  4. choose the best alternative and selling to the management

the aim of investigation is for stable or to show real problem that happen beside as a way an analys to understand deeply their system.

Constraint inside investigation system, is :

· Time, analys minus of time resources for cost

· Cost, related to the time of investigation, so there are limit cost

· Knowledge, system information manager ordered junior analys that not quite in knowledge to observe, so impact with investigation result that can be minus.

· Politics, management or other side propagate issues for obstruct investigation activity

· Interference, there are the other side wants to arrange in investigation activity that cause confesion

Recommendation

· Not take an action if there are no a problem

· Doing a protection with small problems

· Improving user capability or user skill in running or using information system.

· Allowing for modification totally system, so need idea to change it with a new system.

· Put a happen problem into system development plan.

Investigation tactics

Listen, do not lecture

do not presolve the problem

compare stories

look for reluctant responses

probe for logical inconsistencies

observe your effect

expect hard, boring work

avoid politics

 
investigation techniques, include activity of :
· direct internal probes, with 3 
technique direct investigation, there are :
o questionnaires
o interview
o observation
· indirect external probes, there are 
o procedure flow
o document review
o sampling
o Tabular tools
 
Description system nowadays, that explain 
a. inputs
b. outputs
c. files
d. data elements
e. transaction and action document volume
f. data flow diagrams
 
 
REQUIREMENT ANALYSIS
 
There are 4 goal to reach in this phase, that is
· Explain the system completely
· Describing the ideal system
· Taking the ideal system to nowadays system 
with take care of the problems
· Give support user conviction in 
system development team
 
The phase of requirement analysis are interaction 
phase intensive between analys and end-user where system development team use their skill to get reaction 
and trust from user, so can give good participation.
 
Method in requirement analysis
· interviews, 
· questionnaires, 
· observation, 
· procedure analysis, 
· document survey.
 
Sampling
Sampling can use for help decrease time and cost. 
to choose sample of population, there are need 
carefulness so will not fail.
 
Resources problem
· Time
· Money
· Skill
· Technology
· External factor
 
Requirement analysis document
· Analysis conduct
· User requirement
· Constraint system
· documentation
 
 
GENERATING SYTEMS ALTERNATIVES
Selection of strategic

Distributed versus centralized processing

Integrated versus dispersed databases

Surround strategy of system development

 
Selection of tactics
· Now or later
o Technology
o Current cash
o Resources skill
o politic
· Change VS modification
· Configuration SLDC
 
Eight selection of operational planning
Selection of planning consist to 3 group, that is input, processing, and output. There are :
a. Input
   1. On-line versus off-line data entry.
   2. Keyed versus machine-readable data entry.
   3. Centralized versus decentralized data entry. 
b. Processing
   4. Batch versus real-time record update.
   5. Sequential versus direct access to records.
   6. Single versus multiple-user update of records.
c. Ouput
   7. Traditional versus turnaround documents.
   8. Structured versus inquiry-based reports.
      
SELECTING THE PROPER SYSTEM

Comparing tactic : the system is compared based on cost and profit according to relative.

It is 3 ways the A system can be says “more superior then other system” if:

Ø A have a lower cost than B, and have same profit

Ø A have a lower cost than B and higher profit then B

Ø Both of the system have same cost but A have higher profit than B.

 
Selling information system to 
the management as projected benefits 
has two problem, there are :
· Difficult to estimate quantity benefits
· If benefits estimated as quantity, 
rarely form in money 
 
Why important to translate become profit 
to measurable dollars? There are 3 reason :
· Company keep track money with 
traditional accountancy system
· Alternative information system compare 
with another alternative other area in company
· Top management decide to development system 
or not.
 

Cost Category

a. Hardware 
b. Software
c. People 
d. Supplies 
e. Telecommunications 
f. Physical site
 

Nature of costs

Comparing system information cost with system life, 
analys projecting how much changes cost for future. 
There 2 model cost operation system information :
a. Linear.
b. Exponential.
c. Step function.
 

Method for comparation system, there is:

a. Break-even analysis (BEP)
b. Payback period
c. Discounted payback period
d. Internal rate of return (IRR).
 
 

STUDI SISTEM

 
Problem statement
1. Nature of the problem detected 
(for example, increasing data entry backlogs).
2. How problem was detected 
(for example, customer complaints or 
performance measurement system).
3. Impact of problem on organizational goals 
(for example, delays processing of customer orders 
or reduces cash flow).
4. Departments and functions involved 
(for example, marketing department and 
order processing section of production department).
 
Existing system documentation
1. System function and interrelationships 
(this can be done with a graphic tools, 
such as a phyical data flow diagram, accompanied 
by step-by-step narrative description).
2. Processing volumes by type of document.
3. Processing times by type of document.
4. Bottlenecks (distribution of backlogs).
5. Organization policies affecting processing 
(example, a policy requiring that clerks process 
all commercial orders before residential orders).
6. Processing constraints.
   o People (for example, an average 20 percent 
       vacancy rate among data entry operators).
   o Hardware.
   o Software.
   o Development funds.
7. Organization of involved departments and 
function(for example,an organizational chart).
 
Problem correction alternatives
1. Procedure for generating information systems 
alternatives.
2. Cost determination for different alternatives.
3. Feasibility analysis.
   o Break-even years.
   o Payback years or discounted payback years.
   o Internal rate of return.
4. Qualitative factors.
5. Alternative recommended and why.
6. Alternative comparison with firm's goals 
(for example, ROI).
 
Recommended solution
1. Overall system description 
for recommended alternative.
2. New system functions and relationships 
(for example, logical data flow diagram).
3. Expected new system results.
   o Costs.
   o Benefits.
4. Proposed development schedule.
5. Development resource needs.
 
Docummentation
1. Physical and logical data flow diagrams.
2. Processing flow statistics 
(volume, timing, and so on).
3. Organizational charts.
4. Feasibility analysis details.
5. Development project schedule chart.
6. Development project proposed cost schedule.

Here are some guidelines for presenting the system study successfully :

· conduct short presentation

· reduce detail description technique

· represented clearly with visual tool

· bring workstation portable

· emphasized advantage from information system with a few existing alternative according to condition of atural company

Go / No-go decision

        If the company decide to developmney the system,
then information department will do next process,
its a design process sistem.

– If not, the System Development Life Cycle (SDLC)
will be stop.

– Frequently will be found problem with
studying system and generally top management 
will ask to re-working with studying system

– Model will explain some stage part which
repeat and sometimes information department
will make decision repeating the stage before 
explain studying system

– With alternative, decision for repeating
a SDLC stage previously or not is called 
Go – No –Go Decision






Reference:
  • Slide PPT Pengamatan Awal, Kebutuhan Analisis; Ngurah Agus Sanjaya ER, S.KOM, M.KOM
  • http://kuliah.dinus.ac.id/ika/asi.html

komputer vs hari raya

hix..
hixx..

laptop q tak kunjung benar, eh.. yang ada malah komputer hang stlah di dfrag..
menyebalkan c.. yah maw digimanain lagi

mana hari raya datang silih berganti,
yang ada dibanding mikirin komputer dan tugas..
malah harus numplek ama jejaitan dan tandingan..

tapi aku mang hanya bisa pasrah sih..
namanya juga hari raya,,
ada senengnya juga,bisa lancar bikin sampian
hehe...

nyepi nya juga lumayan, meski puasa tak full 1 hari
aku bisa menikmati istirahat dari kepenatan..

yang pasti besok kuningan, jadi harus bangun pagi untuk mebanten...

'met kuningan..'

Minggu, 08 Maret 2009

akhirnya...

huih..

akhirnya bisa ngenet lagi!!!
merdeka!!!

kemaren koneksi internet dirumah mati, bikin q tak bisa browsing chating dkk deh..
males n bete booo...

blum lagi laptop yang mendadak skak mat,.
n harus diinstall ulang
sayang nya tak puna cd na..

finally,,
bisa ngenet dengan sukses nya...

^^

Third Quiz in ADSI

System Development

System development can be interpreted as compilation of new system for replacing the all of old system or repairing the existing system.

The important of system development is :

  • Existence of problems at the old system, that can be the form of
    • An error
    • Growth of Organization
  • To reach for the opportunity
  • Existence of instructions from directives

The purpose of system development

  • To resolving the existence of problems
  • Reach for the opportunity
  • Fulfilling the existence of instructions

The organization’s expectation after implementing an information system

After developing the system, the expectation is upgrading level connected with

  • Performance. Upgrading the result of job activity in new system, until its more effective. Performance can be measured from throughput and response time.
  • Information. Upgrading of information quality that given.
  • Economy. Upgrading in benefit or advantages or decreases cost happen.
  • Control. Upgrading in control for detection and repairing the mistakes that happen.
  • Efficiency. Upgrading of operation efficiency.
  • Services. Upgrading of service that given by system.

The principles of developing an information system

  • Developed system is management
  • Developed system is big capital investment by considering to
    • investigation of all the alternatives
    • the best investment has to valuable
  • Developed system is require an educated people
  • Activity step and duty must be conducted in the process of system development
  • the process of system development doesn’t have in sequence
  • don’t afraid to canceled the project
  • the documentation has to be performed to guidance in system development

There are many of system development life cycle models. three of them is

  1. Waterfall model

The waterfall model is a sequential development process, in which development is seen as flowing steadily downwards (like a waterfall) through the phases of Conception, Initiation, Analysis, Design (validation), Construction, Testing and maintenance.

The first formal description of the waterfall model is often cited to be an article published in 1970 by Winston W. Royce (1929–1995). In Royce's original waterfall model, the following phases are followed in order:



To follow the waterfall model, one proceeds from one phase to the next in a purely sequential manner. For example, one first completes requirements specification, which are set in stone. When the requirements are fully completed, one proceeds to design. The software in question is designed and a blueprint is drawn for implementers (coders) to follow — this design should be a plan for implementing the requirements given. When the design is fully completed, an implementation of that design is made by coders. Towards the later stages of this implementation phase, disparate software components produced are combined to introduce new functionality and remove errors.

2. Iterative and incremental development

Iterative and Incremental development is a cyclic software development process developed in response to the weaknesses of the waterfall model. It starts with an initial planning and ends with deployment with the cyclic interaction in between.

Incremental development is a scheduling and staging strategy, in which the various parts of the system are developed at different times or rates, and integrated as they are completed. It does not imply, require nor preclude iterative development or waterfall development - both of those are rework strategies. The alternative to incremental development is to develop the entire system with a "big bang" integration.

Iterative development is a rework scheduling strategy in which time is set aside to revise and improve parts of the system. It does not presuppose incremental development, but works very well with it. A typical difference is that the output from an increment is not necessarily subject to further refinement, and its testing or user feedback is not used as input for revising the plans or specifications of the successive increments. On the contrary, the output from an iteration is examined for modification, and especially for revising the targets of the successive iterations


  1. Spiral model

The spiral model is a software development process combining elements of both design and prototyping-in-stages, in an effort to combine advantages of top-down and bottom-up concepts. Also known as the spiral lifecycle model, it is a systems development method (SDM) used in information technology (IT). This model of development combines the features of the prototyping model and the waterfall model. The spiral model is intended for large, expensive and complicated projects.

The steps in the spiral model can be generalized as follows:

  1. The new system requirements are defined in as much detail as possible. This usually involves interviewing a number of users representing all the external or internal users and other aspects of the existing system.
  2. A preliminary design is created for the new system.
  3. A first prototype of the new system is constructed from the preliminary design. This is usually a scaled-down system, and represents an approximation of the characteristics of the final product.
  4. A second prototype is evolved by a fourfold procedure:
    1. evaluating the first prototype in terms of its strengths, weaknesses, and risks;
    2. defining the requirements of the second prototype;
    3. planning and designing the second prototype;
    4. constructing and testing the second prototype.

Approaches of developing a system

There are several approach for developing a system, that is :

- Looked into the methodology that used is

- Classical approach. This methodology approach, developing system with following the steps in system life cycle, is approach inside system development by following adequate technique.

- Structured approach. This methodology approach, basically trying to provide to the system analysis addition of tools and techniques for developing the system beside remain to follow idea of system life cycle.

- Looked into the reached target

- Piecemeal Approach, is approach system development emphasize to an event or application.

- Systems Approach, observe information system as an integrated unity for each event or application.

- looked into the way of determining requirement of system :

- Bottom Up Approach, started from low level organization, that is operational level where the transaction done.

- Top-down approach, started from high level organization, that is strategic planning level.

- looked into how to developing:

- Total-system approach, is approach developing system totally at once time.

- Modular approach. this approach try to breaking complicated system into some simple part or module, so the system is easier to understand and developed.

- looked into the technology that used is :

- Great Loop Approach, applying all change at once time with using sophisticated technology.

- Evolution Approach, applying sophisticated only for applications just needing at that moment and will developing for next periods following the requirements according to growth of existing technology.

the meaning of methodology, method and algorithm is :

  • Methodology is methods unit, procedures , job concepts , rules, and postulates that used for a knowledge, art, or other discipline.
  • method is a manner or systematic technique to do something.
  • Algorithm is the sequence procedure that given by a methodology for resolving the problem.

Methodologies of system development classified become three group :

1. Functional Decomposition Methodologies. This methodology is emphasize in system solver into smaller subsystems, until it is easier to understand, planning and implementation.

2. Data Oriented Methodologies. This methodology is emphasize in characteristic of data that would have proceed. This methodology separate become two class, that is :

  • Data-flow oriented methodologies. Generally, This methodology based on system solver into modules that based on the type of data element and behavior of its module logic inside the system.
  • Data-structured oriented methodologies. This methodologies has emphasize structure from input and output in system. Then, this structure will used as basic structure from its system. Function relational between module or system elements explained from the structure system.

3. Prescriptive Methodologies

Included this methodologies is :

  • ISDOS, is developed software by university of Michigan. The ability of ISDOS is automatic the process of development system.
  • PLEXSYS. The ability of PLEXSYS is to do transformation a language of high level computer language into an executable code for a configuration the hardware that expected.
  • PRIDE offered by a company in united state, that is M. Bryce & Ass. Pride is a great compilation software for analysis or design structured system, management data, project management and documentation.
  • SDM /70 or Systems Development Methodology /70 developed and propagated by a company in united state. This methodology is a software that has content with collection of method, estimation, documentation, and administration instruction for helping user to developing and take care of system
  • SPECTRUM
  • SRES and SREM

tools for developing a system can be :

1. Graph, that is : HIPO, DFD, SADT, W/O, JSD

2. Chart, that is : activity charting (systems flowchart, program flowchart, paperwork flowchart or called as for flowchart, database relationship flowchart, process flowchat, gantt chart), layaout chating, and personal relationship charting.


there are many techniques used in developing a system :

  • project management techniques, that is : CPM (critical path method) and PERT(Program Evaluation and review technique) . This technique used for project scheduling.
  • fact finding techniques, technique that can used for collecting the data and finding facts in learning event the exist system. this techniques include : interview, observation, questionnaires, sampling.
  • cost-effectiveness analysis (or cost-benefit analysis)
  • meeting perform technique
  • walkthrough


the differences of being a system analyst and a programmer and also mention what are the knowledge a system analyst should posses

System analyst is the person who analyzing system (learn how the problems arise and determining requirements user of system) for identification possible resolving. Otherwise, a programmer is person create the program code for an application pursuant to building design which have been made by system analyst.

The knowledge a system analyst should posses is :

  • Knowledge about data processing technique, computer technique, and computer programming.
  • General Knowledge of business
  • Knowledge about the quantitative method
  • Ability in trouble-shooting
  • Ability in communication between personal
  • Ability in constructing relation between personal.

reference :