PART IV: ANALYSIS AND DESIGN OF INFORMATION SYSTEM

INITIAL INVESTIGATION AND ANALYSIS REQUIREMENT

INVESTIGATION SYSTEM CONCEPTS

Problem is difference distinctive (gap) among system aim and condition of system which actually, with other savvy why system fails to reaching to the effect system already being determined previous.

To know things any kind has already caused system failing, so an analyst advisable to do investigation earlier before do action to fix system. With investigation, an analyst will more understand problem and its system path more visceral, even in detect problem was known about problem its but still figure its outline.

There are many reporting in detects problem maybe don't quite a real or indissoluble. That thing maybe because of:

To the effect that over ideal so difficult or maybe won't be reached.

• System can't be developed since resource lack, attitude or both

• Inaccurate system measurement.

• statement of goals is dated

• The difference among idle system and temporary system

- Problem solving

• System condition formulation that walking through activity investigation in detail

• Getting ideal system consensus.

• Develop severally alternative to reduce the difference (gap) among ideal system with system that be walks.

• Choosing the best one alternative

To the effect of investigation that is subject to be strengthens or points out problem that actually happens over and above as trick an analyst for understands its system exhaustively.

CONSTRAINT IN INVESTIGATION SYSTEM

In do investigation some constraint which often emerges is:

• Time
 Analyst time comes up short resource, so just does play favorites investigation activity. Usually time is engaged cost problem be needed.   

• Cost
 Cost oftentimes that is issued is engaged the duration time for activity to investigation, so management will give cost limitation.

• Knowledge
 Manager is information system tends to enjoin junior analyst that haven't had technical or science membership that adequately, so will impacted on investigation result that visceral subtracted ,ripe or complete. 

• Politics
 Management or particular parties may broadcast issue that its aim to constrain investigation activity.

    • Interference

RECOMMENDATION

Result of investigation is one recommendation, one that one of it is as follows:

• Don't take action whatever since undiscovered problem.  

• Doing preserve system for problem what do little.

• Increasing ability or user skill at deep going or utilizes information system.    

• Regarding for system modification totally, so needs thinking to substitute it with system a new one.

• Placing happening problem into systems developmental plan which shortly be done.

INVESTIGATION TACTICS

Why needs tactics?

• Find all problem

• Knowing its appearance cause problem

• Determining solution in point

Done so all system element can accept solution offer without trouble their activity

Severally tactics which can be done:

• Listening system agent opinion

• Don't give startup resolving

• Comparing story some bodies system agent to same case

• Notice the logical inconsistent problem

INVESTIGATION TECHNIQUE

Investigation Technique to cover activity:

Directly, is to know face to face what which happen deep environmental user.

• Questioner

• Question-answer

• Monitoring

Indirectly, Activity who can presto do and invisibility of personal operational, so gets to know extern or something flank that disguised of user community. This activity will dominate in the early activity SDLC, hereafter internal probe to deepen.

• Procedural flow

• Studying document

• Sample

• Tabular

CURRENT SYSTEM DESCRIPTION

Determining current system performance will struck a snag if firm have no one performance measurement default system. Too bad, tending firm doesn't update to document walking system. Hence, analyst fix document up to problem investigation system. Current system description covers explanation:

• inputs

• outputs

• files

• data elements

• transaction volume and action document

• data flow diagrams

ANALYSIS REQUIREMENT

Intensive interaction phase among analyst system with end user where development systems team point out its membership to get comment and user trust so gets good participation.

4 goal that want to be reached :

• Wording comprehensive system

• Figuring ideal information system

• Taking in ideal information system to condition of currently by notices resource constraint

•  Giving push to wearing confidence into development system

Method

• Question-answer

• Questioner

• Observation

• analysis procedure

• Document monitoring

Resource constraint

• Time

• Money

• Membership

• Technology

• External factor

Document is analysis the need

• Analysis direction: Relationship with end user, monitoring processes, about problem in data collecting

• Wearing requirement: Real requirement, Write-up requirement, training requirement and new system influence

• System constraint: Wording time and cost constraint, membership, technology and external factor

•  Document as instrumental as data collecting, statistical consensus, ala data flow logical and physical, early data element in lexical data.

GENERATING SYSTEMS ALTERNATIVES

How to current system condition approaching with condition of system which ideal?

• Making alternative to solve information system problem

• That best alternative is applied one expedient

Strategy Selection

• distributed versus centralized processing

• Changing information decision from centralized processing's data goes to decentralized end user responsibility center

• Integrated versus dispersed is database

• System designer shall regard data any kind ingoing in base's data and one turns in at File

• Surround Strategy of System Development

• Environmentally surrounding strategy is of important in term confiscation because information system of other firm may in contrast to corporate currently.

Tactics Selection

Done before operational scheme option

Operational scheme Selection

Scheme selection can be agglomerated into

o Input

§ Online Vs Off Line Data Entry

§ Keyed Vs Machine Readable Data Entry

§ Centralized Vs Decentralized Data Entry

o Processing

§ Batch Vs Realtime record update

§ Sequential Vs Direct Access to records

§ Single Vs Multiple User update of records

o Output

§ Traditional Vs Turn Around Documents

§ Structured Vs Inquiry based reports

SELECTING THE PROPER SYSTEM

Tactics compares: System than bases cost and gain relatively; There is 3 A's system trick is said more superior with another system if:

• A have inferior cost of B and gain both same

• A have inferior cost of B and A. result more gain A lot of B

• A and B have cost with but resulting gain A. more A lot of B.

Several Comparative Method system

• Break Even point Analyisis

• Payback Period

• Discounted PayBack period

• Internal Rate of Return

Cost Category

§ Hardware

§ Software

§ People

§ Suppliers

§ Teleccommunications

§ Physical sites

Cost Detail

Comparing system information cost via system life, projection analyst gets what change cost for the future and there is 3 information system cost models which is Linear, Exponential and Step Function.

System Information Cost can happen really just and gets too happening chronically.

• Information system cost happening once just which is on-time cost and development cost what do happen while development system.
• Information system cost happening continually among those is recurring cost and operational cost where this cost happens while operating information system everyday

INFORMATION SYSTEM FACTOR

Qualitative Factor That Aim Good Information System Performance among Those

• Reducing fault zoom
• Reducing time to fix fault
• Reducing response time from workstation alternative
• Hastening supplying time information
• Increasing system security
• Increasing record's source update active
• Increasing wearing satisfaction

CORPORATE STRATEGY FACTOR

• Consumer satisfaction
• Sell zoom increases
• Consumer commitment and vendor
• Product marketing information

REPRESENTATION IS LEARNING SYSTEM

• Doing presentation in few words
• Reducing with technically explanation detail
• Representation is ala is clear with visual's assistive tool
• If utilizes model to utilize assistive tool e.g. laptop so more informative
• Emphasize gain of information system proposal with severally alternative whatever available appropriate condition which experienced by company.

DECISION DRAWNS OUT OR NOT

• If firm decides to develop system therefore information department will do succeeding process which is System Design Process.
• If contrariwise therefore System Development Life Cycle (SDLC) will be discontinued.
• Oft will find problem with study system and usually top management will ask for to do its reworking to study system.
• Model will word some part step which and sometimes information department will make repeat decision step before word study system.
• With alternative, decision for repeat one SDLC'S step in advance or not been called Go – No. –Go Decision.

PART III: ANALYSIS AND DESIGN OF INFORMATION SYSTEM

CHAPTER 2: REVIEW GENERICALLY SYSTEM DEVELOPMENT

1. The Importance Of Developing An Information System
System development can mean to arrange a system a new one to replace old system as a whole. It’s required of development system because:
1. there is a problem,the appear a problem as:

· Error

Error in old system causes a old system can't operating according to that exepected.
· Organizationl growth
Causative organization growth has to be arranged by a new system . As requirement of information more that extensive,volume processing data is gotten worked up ,changing accounting a new principle . There is changing it, therefore causes a old system is not effective again.

2. To reach for opportunities

In a state competing market, information speed or time efficiency really determine success or not strategy and plan was arranged to reach for aught opportunities.

3. directives
Composing a new system would be done because instruction from on top of management or from outside environment.

2. The purpose or goal of developing an information system
To the effect in system development, which is:

• To solve a problem
• Reaching for opportunities
• Instruction pock that is given

3. The organization’s expectations after implementing an information system

• Performance: Performance can be measured from throughput and response time. Throughtput is foot up from work who can be done at the moment particular. Response time an average time which is delayed transactions betwixt or enhanced work by its time comment to comment that work.
• Information: Increase to information quality is given
• Economic: Increase to benefits or happening decreasing cost.
• Efficiency: Increase for efiensi to had out. Efficiency in contrast to economic. Economic in reference to resource which is utilized, meanwhile efficiency is engaged how that resource utilized by the most dissipation minimum.
• Service : Increase to service that gave by system

4. The principles of developing an information system

• System for management :

After system is developed, then will utilize information of this system is management. So system has to get back up needful requirement by management.

• System is big capital investment

• All aught alternative shall be invested (opportunity cost that lost)

• The best one investment shall well worth

This investment is new being said advantages if valuably with the meaning benefit or result turn back to be even greater from cost to get it. Cost benefit analysis or cost effectiveness analysis can be utilized to determine if that investment project valuably or not.

• System requires educated person

Man constitutes successful prescriptive prime factor don't it a system, well in its development process, its implement, and also in its operation process. Therefore person that engages in development and also this system purpose has to be taught, taught here is not meaning have formal education.

• Job and duty assignment step that shall be done in system development process.

Systems Development Life Cycle

• Systems developmental process hasn't well organized

For example, one processing time of hardware's procurement is done, pettily processes another system development discontinued just umtuk wait for its coming hardware that needed, but gets to be done by another scheme that don't depend with hardware's existence.

• Don't fear to cancel project

Decision to continue or cancel is true have to be evaluated the carefully. For the case of certain, where a project cannot help discontinued or canceled because have improper again, hence must be done emphatically.

• Documentation that is made and is gathered up to process of system development can be utilized for communication material among system analyst with wearing system and gets to be utilized to push system involvement.

5. Three system development life cycle models

1. Waterfall Model

Explanation:

This waterfall's model constitute one way model that is begun from analysis's step,design, implementation, verification, and maintenance.

• Analysis

Search process is the need and is focused on software. To know character of program who will be made, therefore softwares engineer shall understand about domain information of software, e.g. function which is needed, user interface, etcetera. Of 2 that activity (sought after system and software requirement) shall be documented and is pointed out to customer. Implementation / coding

• Design

This process is utilized to change requirements upon becomes representasi before coding is begun. Design shall get mengimplementasikan requirement already being named on previous phase. As 2 previous activities, therefore this process shall also be documented as configuration of software.

• Implementation

To get apprehended by machine, in this case is computer, therefore previous design shall be transformed its as understandable form by machine, which is into programming languages via processes coding. This phase constitute implementation of design's phase that technically its following worked by programmer.

• Verification

Something that is made has experiment. Such even with software. All software functions that experiment shall, that software releases from error, and its result shall aptly correspond to requirement already be defined previous.

• Maintenance

Preserve a software required, including in it is developmental, since software that is made is not all along just such a. While is carried on maybe just extant errors little that undiscovered previous, or there is feature increase that haven't available on that software. Needful development while marks sense changing of external corporate as when available operating system commutation, or another peripheral.

2. Iteratif Model
















Explanation:
The difference of model waterfall is of process system development job it. If on waterfall's model happens one way, meanwhile on iteratif's model happens repetitive ala, herein available increase testing and evaluation that tests if that application still available fault or not. If system that apparently have fault therefore will do problem identification again and back to to be developed.

3. Spiral Model

















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 usual 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. Th 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:

• evaluating the first prototype in terms of its strengths, weaknesses, and risks;
• defining the requirements of the second prototype.
• planning and designing the second prototype.
• constructing and testing the second prototype

6. Approaches of developing a system
There are some approaching to system development, which is:

• Classical approach vs approach structured : So-called classical approach even with approach tradisonal or conventional approach is approach at deep system development which follow steps at cycle system lives without dibekali with tools and tech that is equal to. Meanwhile Approach most structure was proveded with by tool and needed tech deep system development, so result a stop to system which is developed will get system that most its structure is defined with every consideration and clear.

• Piecemeal approach vs systems approach : Piecemeal approach is constitute system development approach that emphasizes at one particular activity or application most indeed. Mean while system approach notice information system as one terintergrasi's unity for each one activity or its application.

• Bottom-up approach vs top-down approach : Approach is bottom-up ascends to be begun from organization bottom level, which is operational level where transactions is done. This approach is begun from requirement formulation to handle transactionses and on the up grade to levels on with formulate information requirement bases that transactions. Mean while approach on top down to be begun from level on organization, which is strategy planning level. This approach began by defines target and organization wisdom. Succeeding stage be been done its analysis is information the need. After information requirement is determined, therefore process is down go to transaction processing, which is determination output, input, database, operating procedures and control.

• Total-system approach vs modular's approach : Total system approach constitute approach that develop concomitant system thoroughly. Mean while modular’s approach constitutes approach that tries to break down elaborate system as some part or module that modestly, so system will more perspicuous and developed

• Great loop approach vs evolutionary approach : Great loop approach applies changing comprehensive concomitanting to utilize sophisticated technology. Meanwhile amends Approach apply sophisticated technology strictly for application which require even at that moment and will continually be developed for period next follow its requirement correspond to aught technology developings.

7. The meaning of methodology, method and algorithm

• Methodology is unitary method which utilized by a scholarships.
• Method is someway, tech that sistematik to work something.
• Algorithm is Medley procedure to solve a period.

8. The three classifications of development methodology

• Functional decomposition methodologies

• Emphasizing system resolving becomes subsystem
• Example: HIPO, Stepwise refinement (RS), iterative stepwise refinement (ISR), information hiding.

• data oriented Methodologies

• Emphasize on processed data characteristic.

• data flow oriented's Methodologies: types appropriate modules data elements Example: SADT (Structure Analysis and Design Techniques), Composite Design, Structured Systems analysis and design(SSAD)

• data structure oriented's Methodologies: input structure and output. Example: JSD (Jakson’s Systems Development), W/O (Warnier/Orr)
  

• Prescriptive

• Usually been provided by software maker factory

• ISDOS (Information System Design and Optimization System)

• PLEXSYS

• PRIDE

• SDM/70 (Systems Development Methodology/70)

• SPECTRUM

• SRES dan SREM

• Beberapa prescriptive methodologies yang lainnya

9. Mention tools for developing a system

• Systems development tools which get graph form amongst those:

• HIPO is diagram
• flow's data diagram
• Structured chart
• SADT
• Warnier / Orr is diagram
• Jakson ’ s diagrams

• Tool that utilizes to design:

• Activity charting

• Systems flowchart
• flowchart's program that as:

• logic flowchart's program
• Detail computer programs flowchart

• Paperwork flowchart or form flochart

• relationship flowchart's database

• Process flowchart

• Gantt chart

• Layout charting

• Personal relationship charting

• Working distribution chart

• Organization chart

10. Techniques used in developing a system

• Project management techniques: for scheduling to project, example: CPM and pert
• Fact finding techniques: to gather and determines fact. Its tech: Interview, Observation, questionnaires, sampling
• analisis's tech cost / benefit: cost benefit analysis and cost effectiveness analysis
• tech for going meeting

11. The differences of being a system analyst and a programmer and also mention what are the knowledge a system analyst should process.

• Analysis is system and Pemrogram

System analyst: person that analyse system or studies problems and determine system user requirements to identify well-grounded resolving.

Pemrogrammer: person that write program code for a given application bases engineering that made by system analyst.

System analyst on call bridges distinctive happening science among system user and pemrogrammer

• knowledge a system analyst should process

A System Analyst shall have ability and knowledge as:

• Data processing tech, computer's technology and computer's mathematics.
• Science about bosnis in common
• Science about quantitative method
• Trouble-shooting membership
• Communication membership among person
• membership builds relationship among person

References:

http://en.wikipedia.org/wiki/Spiral_model

Hartono, Jogiyanto.2005.Analisis dan Desain Sistem Informasi: Pendekatan Terstruktur, Teori dan Praktik Aplikasi Bisnis. Yogyakarta: Andi.

http://hansiaditya.wordpress.com/2007/09/25/waterfall-process-model/

http://elista.akprind.ac.id/upload/files/3098_MATERI_1.PDF