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NORMALIZATION-QUIZ SEVENTH

2009-05-03T07:06:00.000-07:00

THE ERD:

Normalization of erd:

First Normal Form (1NF)

A table on the form said to be normal if I did not reside in the unnormalized form of a table, where there is a kind of field multiplication and field that allows a null (empty).

Second Normal Form (2NF)

Normal form 2NF met in a table if it meets the form of 1NF, and all the attributes than the primary key, have a full Functional Dependency on primary key. A table does not meet 2NF said, if there are attributes that Functional Dependency are only partial (only depending on the part of the primary key). If there are attributes that have no dependence on the primary key, then the attributes must be moved or removed.

3NF (Third Normal Form)

Normal form 3NF fufilled if have fulfilled form 2NF, and otherwise there is attribute of is non key primary owning depended to attribute of is non the other key primary.

DATABASE NORMALIZATION

2009-04-26T01:21:00.000-07:00

Database Design Process

Gathering user or business requirement
Developing E-R Model bases user or business requirements
Convert E-R Model goes to relationship gatherings (table)
Normalization is relationship to remove anomaly
Implementation goes to database by make table for each relationship already most normalization

Database Normalization

Why done by normalization?

Optimizing is table structures

Increasing speed
Removing same data inclusion
More efficient in storage media purpose
Reducing redundancy
Avoiding anomaly( insertion anomalies , deletion anomalies , anomalies update ).
Increased data integrity

One table is said well (efficient) or normal if pock 3 criterions as follows:

If there is decomposition table, therefore decomposition it shall be secured safe( Lossless Join Decomposition ). Its mean, after that table is untied / at decomposition becomes new tables, that new tables can result tables originally equally a hair breadth.
It's petted dependable functional at the moment data change (Dependency Preservation).
Don't breach Boyce Code Form Normal (BCNF).

If the third criterion (BCNF) can't be accomplished, therefore at least that table not breach the third phase Normal Form (3rd is Normal Form or 3NF).

Functional Dependency

Functional Dependency to figuring attribute connection in a relation.
A attribute is functionally dependant in other, if we used that attributes value for defined the other attributes value.
The symbol is "->" for represent the functional dependency.
Notation : A -> B
A and B are attribute from a table. The mean is with functional A defined B or B depends on A, if and only if there are 2 line data with the same value A, so value B is same.

Functional Dependency:
NRP -> Nama
Mata_Kuliah, NRP -> Nilai
Non Functional Dependency:
Mata_Kuliah -> NRP
NRP -> Nilai

Functional Dependency from table value :

NRP -> Nama

Because for every value the same NRP, so the same value is same.

{mata_kuliah,NRP} -> Nilai
Because attribute value depends on mata_kuliah and NRP together.

In the other mean for mata_kuliah and the same NRP, so the value is same, because mata_kuliah and NRP is key (unique).

First Normal Form (1NF)

A table on the form said to be normal if I did not reside in the unnormalized form of a table, where there is a kind of field multiplication and field that allows a null (empty).

Is not allowed there :

- Many attributes of value (Multivalued attributes).

- Attributes composite or a combination of both.

So :

- Price is the domain attribute must be atomic rates

Example the following Student Data :

Table-the table above doesnt meet the requirements 1NF

Decomposition to be :

Student Table :

Hobby Table :

Second Normal Form (2NF)

Functional dependency X --> Y if it is said of a remove attribute A from X means that Y is no longer dependent functional.
Functional dependency X --> Y if it is said partial delete an attribute A from X means that Y is functionally dependent.
Relation scheme R in the form 2NF if every non-primary key attribute A Î R is functionally dependent on the full primary key R.

3NF (Third Normal Form)

Normal form 3NF fufilled if have fulfilled form 2NF, and otherwise there is attribute of is non key primary owning depended to attribute of is non the other key primary.
Tables of up to standard student following 2NF, but do not fulfill 3NF :

Boyce-Codd Normal Form (BNCF)

Boyce-Codd normal form (or BCNF) is a normal form used in database normalization.
It is a slightly stronger version of the third normal form (3NF). A table is in Boyce-Codd normal form if and only if, for every one of its non-trivial functional dependencies X → Y, X is a superkey-that is, X is either a candidate key or a superset thereof.

Fourth and fifth Normal Form

Relationship in fourth normal form (4NF) if relationship in BCNF and not contains multi value dependency. To remove multi value dependency from one relationship, we are divide relationship become two new relationships. Each relationship contains of two attributes have multi value relationship.

Relationship in fifth normal form (5NF) get business with property is calling join without marks sense information loss (lossless join). The fifth normal Form (5 NF) also know as PJNF (projection join normal form). This case is very rare to appearance and hard to detect practically.

Refer:
Agus Sanjaya ER, S.Kom, M.Kom, slide presentation : Normalization

DATABASE AND ERD

2009-04-19T06:20:00.000-07:00

DATABASE AND ERD

Definition of Database
• Collection of data which stored in magnetic disk, optical disk or other secondary storage.
• Collection of data which is linked one to other of an enterprise.(factory, govermental institution, or private section).
• Manufactur company : production planning data, actual production data, data ordering material.
• Hospital : data of patient, doctor, nurse, etc.

Database Management System
• Collection a database with software application in based of database.
• This software application is use for accessing and maintaining the database.
• The first aim of DBMS is to preparing an easy and efficient environment for using, collecting, and storing data and information.
Bit, Byte, Field
• Data bit is the part that contains the smallest value of 0 or 1.
• Bytes-bit set of bit similar.
• Field set of byte-byte similar, in the database used the term attribute.

Attribute or Field
Attribute is the nature or characteristics of an entity that provides provide detail on these entities. A relationship can also have attributes.
Example attributes :
• STUDENTS: NIM, NAME, ADDRESS
• CAR: NOMOR_PLAT, COLOR, TYPE, CC

Types of Attribute
Single vs Multivalue
• Single -> only can containing mostly 1 value
• Multivalue -> can containing more than 1 value with same kind value
Atomic vs Composition
• Atomic -> cannot divided into smaller attribute
• Composition -> alliance of smaller attribute
Derived Attribute -> attribute that can be yield from other attribute value, for example age can be yield from attribute of birth datenull
Value attribute -> attribute with no value for a record
• Mandatory value attribute -> attribute that must have a value
record or tupple
• a data row inside a relation
• Consist of attribute collection which attribute interaction for advising entity or relation as detail
Record / Tuple
Record is a data line in a relationship. Record consists of a set of attribute-attribute where the attribute is an attribute-related entity or to inform the full relationship.
Entity / File
Entity is the object or objects in a certain mini world represented in the database. Entity can be:
1. Things that have physical (people, cars, houses, etc.)
2. think that there are conceptual (enterprise, employment, discipline, etc.)
Domain
Domain is the set of values that are allowed to reside in one or more attributes. Each attribute in a database relasional is defined as a domain
Element key of data
Key is element of record that used for finding its in access time or can be used for identification each entity/record/row.
Types of Key
• Superkey represent one or more attribute from tables of able to be used to identify entity/ record of tables uniquely (not all attribute can become superkey)
• Cadidate Key is super of key with minimum attribute. Key Candidate may not contain attribute of other tables so that key candidate beyond question superkey but not yet of course on the contrary.
• Primary Key
One of the attribute of key candidate can be selected/ to be determined to become key primary with three the following criterion:
- The Key more natural to be used as reference
- The Key more simple
- The Key well guaranted it

• Alternate Key is attribute of key candidate which is not chosen become key primary
• Foreign Key represent any attribute subjecting to key primary at other tables. Key Foreign will happened at one particular relationship owning many to one cardinality ( one to many) or many to many ( many to many). Key Foreign usually is always put down by at tables of which is flange to many.
• External of Key represent attribute lexical ( or gathering of lexical attribute) which is it values always identify one object of instance.
Entity Relationship Diagram
ERD is a model of a network that uses word order is stored in the abstract system.
Differences between the DFD and ERD, namely:
1. DFD is a model of network functions that will be implemented by the system.

2. ERD is a model that emphasizes the network data on the structure and relationship data.

The elements of ERD
Entity
• Something exist inside real system or abstract system which data stored or where are the data.
• Symbolized as square of length. There are also line symbol as link between compilation of entity with entity and compilation entity with its attribute.
Relationship
• Natural Relation happened between entity.
• Generally, given name with basic verb that facilitating for reading its relation.
• Symbolized as rhomb
Relationship degree
• Account of entity that participated inside a relationship.
• Degree is often used in ERD\
Attribute
• Characteristic of each entity or relationship
• Symbolized as circle
Cardinality
• Showing maximal account tupel that can be relation with entity in the other one.
Degree Of Relationship
• Unary Relationship
Unary Relationship is model of relationship that happened between entity coming from entity set same.
• Binary Relationship
Binary Relationship is model of relationship that happened between 2 entitas.
• Ternary Relationship
Ternary Relationship representing relationship between instance from 3 type of entitas unilaterall
Cardinality
There are 3 Cardinality relations, namely :

One to One : Level one to one relationship with the one stated in the entity's first event, only had one relationship with one incident in which the two entities and vice versa.
• One to Many or Many to One: Level one to many relationship is the same as the one to many depending on the direction from which the relationship view. For an incident on the first entity can have any relationship with many incident on the second entity, if the one incident on the second entity can only have one relation with the incident on the first entity.
• Many To Many: if any incident occurs in many entity have relationships with other entities in the incident.
Exampel Of Cardinality

Notation (Diagram E-R)
Symbolic notation in diagram of ER is:
• Square of length express gathering of entitas
• Radian express attribute
• Rhombic of relationship gathering expressing
• Mark with lines as link between relationship gathering with gathering of entitas gathering and of Entitas with its attribute

Reference:
1. ER Ngurah Agus Sanjaya. Slide Part 5 - DATABASE DAN ER-DIAGRAM.

QUIZ V: DATA FLOW DIAGRAM

2009-04-05T04:18:00.000-07:00

Data Flow Diagram :

Describe the division of system in a smaller modul.
To make easier a user, who is don't understand a computer aspect to be understanding the system.

Context Diagram :

Consist of a process and drawing a scope of a system.
That is highest level of DFD, which it is drawing all of input to system and output of system.
System limited by boundary (is depicted by dash line).
No storage.

Zero Diagram :

Describe the process from DFD.
Perhaps in this level can be storage data.
For a process, which not dividing again in next level, so we can add symbols '*' or 'P' in the last process numbers.
Balancing of input and output between zero diagram and context diagram have to be looked after.

Detail Diagram :

That is a diagram, that loosen all process in zero diagram or level before.
Numbering level in the system.

In a level, should nothing more than 7 process and maximal 9, if more that it, so we must decomposising.

Specification of Process :

Every process in DFD, must have process specification.
In top level method, that is we use for drawing a process with descriptive sentence.
At more level detailed, that is in underneath process (functional process) need specification, that is more structured.
Specification of process will be guidance for programmer to make program.
The method, which we use in specification process : analysis of process in a story, decision table, decision tree.

External Unity :

A something, that is in external system, but it is giving a data to system or giving data from system.
The symbol is notation box.
External entity is not a part of system.
Naming :
a. The form is terminal's name is noun.
b. Terminal not have a same name, except the object in same.

Data Flow :

Is a information's place.
The symbol is a line, that is to combine a component of system.
Data flow shown with direction bow and line, given name or data flow poured.
Data flow poured between process, data storage and showing data flow from data, that is input for system.
Guidance of giving of name.
a. The name of data flow, consist of some words flow to combine with continued line.
b. No data flow, which the name is same and gifting name must reflecting the containts.
c. Data flow, the consist of some elements can be expressed with group element.
d. Avoid usage of word ‘ data’ and ‘ information’ to give the name of at data flow.
e. As possible the name of data stream written is complete.
Other rule.
a. Data flow name which turn in at a process may not same by the name of secretory data flow of that process.
b. Data flow which step into or go out from data of storage needn't be called by, if :
1 A comprehended easy and simple data flow.
2 Data flow describe all data item.
c. No data's flow of terminal to data of storage or on the contrary because terminal non part of system,terminal relation with
data of storage have to through process.

Process :

Process is what done by system.
The function of process is transformation one or some input data become one or some output data as according to specification
of which is wanted
a. Every process have one or some input and producing one or some output.
b. The process is buble.
Director for gifting the name of process.
a. Name process consist of verb and noun, which it reflecting that function of process.
b. Don't use word process as part of name of a buble.
c. No some process, that have the same name.
d. Process must to give number. Serial number must following the current or serial process, but serial number is not absolute
that is serial process with chronologys.

Data Storage :
Data storage is a storage data's place in system.
That symbol is a pair of parallel line or two line with one of side.
Process can take data from or giving data to database.
Director for gifting the name.
a. The name must reflect data storage.
b. If its name more than one word, so must giving continued sign.

DFD Symbol :

Data Dictionary :

Function to assist perpetrator of system to interpret application in detail and organizational all used by data element is system
precisely so that user and system analyst have is same congeniality base about input, output, depository and process.
At analysis phase, data dictionary used as by communication means between system analyst and user.
At phase scheme of system, data dictionary used to design input, database and report.
Data current at DFD have the character of globally, boldness more detailed can be seen at data dictionary
Data dictionary contain the followings :
a. Name of data flow : must to be noted reader to needing furthermore clarification about a[n data current can look for him easily.
b. Alias : alias of data can be written.
c. Data form : used to group data dictionary.
d. Data flow : showing where from data emit a stream of and where data heading.
e. Explanation : giving clarification about meaning of data current.

Balancing in DFD :

Data flow which come in and out from one process must be same with the data flow which come in and out from specification process at
the level beneath.
The name of data flow which come in and out from one process must be same with the name of data flow which come in and out from that
specification process.
Totals and names of the external entity from one process must be same with totals and names of the external entity of that specifica-
tions process.
Things that must be attended in DFD which has more than one level is :

a. There's must be input and output balancing between one level and the next levels.
b. Balancing between level 0 and level 1 is seen in input/output of the data flow to or from zero level terminal, meanwhile balance
between level 1 and level 2 is seen in input/output of the data flow to or from the process it self.
c. The name of data flow, data storage, and terminal in each levels must be same if their object are same.

Prohibition in DFD :

The data flow may not directly from one external entity to another external entity without any process.
The data flow may not directly from data storage to external entity without any process.
The data flow may not directly from data storage to the other data storage without any process.
The data flow from one process directly go to another process without any data storage should be avoided.

Referensi :
Ngurah Agus Sanjaya, S.KOM, M.KOM. Slide Part 4 - DATA FLOW DIAGRAM

Quiz Four

2009-03-29T01:20:00.000-07:00

INVESTIGATION SYSTEM CONCEPT

There is a system of investigation here also be due to a detection of the problems that the report does not really real, such as:

Too ideal destination
Lack of resources and / or attitude
Measurement system is less accurate
System that is the purpose behind
The difference between the ideal system and the system while

Problem solving:

Decompose the system is running.
Where is the investigation carried out here in detail
Getting a consensus that the ideal system
Developed several alternative
Selecting the best alternative

The objective of the investigation here is to show that the problem actually occurs.

CONSTRAINTS SYSTEM INVESTIGATION

In making an investigation, there are several problems that often arises, namely:

Time
Cost
Science
Politics
Intervention

Recommendation

Result of investigation is a recommendation which is filled with:

Never take any action

This is mean when there is no problems find in system we can’t take any actions.

System maintenance

System maintenance needs to maintenance small problems like when job description not runs very well. So we must solve that problem and after we solve it we must maintenance.

increase ability or user ability
totally consider to system modification
put problem into the development system plan

INVESTIGATION TACTICS

Why need some tactic?

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 TECHNICS

Direct:

Questionnaire
Asking and reply
Observation

Indirect:

Procedure flow
Document studying
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 stage between systems analyze with end user when team development system show their skill to get some reaction and trust the user until the get good participation.

Four goal wish to achieve:

Explain the system completely
Describe the ideal information system
Bring the ideal information system at moment with observe the resource constraint
Give push to user conviction into development system
- Method:
  - Question and Answer
  - Questioner
  - Observation
  - Current procedure
  - Document monitoring

Resource constraint
- Time
- Cash
- Skill
- Technology
- External factor
  - Document analysis requirement
    - Analysis direction: relationship with the end user, process monitoring, problems in data gathering.
    - User needs: real needs, report needs, exercise needs, and new system influence.
    - System constraint: explain time and cost constraint, skill, technology and external factor.
    - Document kind data gathering instrument, statistic consensus, data flow according to physic and logical, first data element in data dictionary.

Generating Systems Alternatives

How to close the system condition at moment with the ideal condition system?

create alternative to solve the information system problem
best alternative to applying accordance with wisely

Strategy selection

Distributed versus centralized processing

Change information decision from centralized data processing to decentralized end user responsibility center.

Integrated versus dispersed database

System planner must consider what kind of incoming data to database and incoming to file.

Surround Strategy of System Development

Environs are important strategy in case overtake company because information system from other company possible different with company at moment.

Selection tactic

Do before operational planner selection started. If we can make some tactic before doing operational planner, we can choose the best tactic to solve the problem.

Operational planner selection

Planner selection is able categorize into:

Input
- Online Vs Off Line Data Entry
- Keyed Vs Machine Readable Data Entry
- Centralized Vs Decentralized Data Entry
  - Processing

Batch Vs Real-time record update
Sequential Vs Direct Access to records
Single Vs Multiple User update of records
- Output
  - Traditional Vs Turn Around Documents
  - Structured Vs Inquiry based reports

SELECTING THE PROPER SYSTEM

Tactics compare the : System compared to by pursuant to expense and advantage relatively. There is 3 way of system A told by more pre-eminent with the other system if

A have the lower expense from B and advantage of both is of equal
A have the lower expense from B and A yield the advantage which is more than B
A And B have the expense of is of equal but advantage yielded by A of more amount

Some Method of Compare System

Break Even point Analyisis
Payback Period
Discounted Payback period
Internal of Rate Of Return

Categories Expense : hardware, software, people, suppliers, telecommunications and physical sites

Expense Detail is comparing expense of information system of passing system life, projection analyst of how many expense change for the future and there is 3 model of expense of information system that is Linear, Eksponensial And Step Function

Expense of information system can just be happened once and earn is also happened chronically.

Expense of just information system that happened once that is ontime cost and development cost that happened system development moment .
Expense of information system that happened continually among other things is reccuring cost and also operational cost of where this expense is happened by the moment of information system operate every day.

FACTORS INTO INFORMATION SYSTEM

Qualitative factors that lead the performance information system that both of them :

Reduce errors
Reduce the time to fix errors
Reducing the response time from the workstation alternative
Accelerating the provision of information
Increase the security system
Have active update source record
Increase user satisfaction

FACTORS INTO CORPORATE STRATEGY

Customer satisfaction
Sales increased
Consumer and vendor commitment
Information marketing products

PRESENTING LEARNING SYSTEM

Make short presentations
Reduce the detail description techniques
Clearly presented with visual aids
If using a model using a tool such as a laptop so that more informative
Emphasize the benefits of the proposed system with some alternative information that is appropriate conditions experienced by the company.

CONTINUING DESICION OR NOT

If the company decided to develop the information system, the department will do next, namely the System Design Process.
If then the System Development Life Cycle (SDLC) will be terminated.
Often the problem will be found with the system and the study and top management will usually ask for the re-employment system to study.
Model will describe some of the stages of the repeated and sometimes the information will make a decision before the repeat stage system of study.
With the alternative, the decision to repeat a previous stage SDLC or not called Go - No-Go Decision.

Referensi:

Slide PPT Pengamatan Awal, Kebutuhan Analisis; Ngurah Agus Sanjaya ER, S.KOM, M.KOM

CHAPTER II: SYSTEM INFORMATION ANALYSIS AND DESIGN

2009-03-07T23:20:00.000-08:00

DEVELOPING AN INFORMATION SYSTEM

1) What is the importance of developing an information system?

System development can be interpreted to arrange a new system to replace the previous system as a whole or repair the existing system. The previous system need to be repaired because of a few things, which is:

a. Problem.
The problem in this system can be in the form of deceits that causes not wealth treasure the safe companies and truth from data is less well guaranted, errors not intentional that causes data truth not well guaranted, the operation not efficient, and not bidding the management policy that applied.
b. Organization Growth.
Organization growth here that is information need more vaster, data processing volume more increase, bew accountancy principle change. Caused by this change, so old ones system not effective again, so that must there development towards system.

2) What is the purpose or goal of developing an information system?

Purpose or goal of developing an information system

- to solving some problems

- reach for opportunity

- fulfilling given instruction

3) What are the organization’s expectations after implementing an information system?

There are the expectations of organization after executing the information system

Performance ( performance)

Measured to use and throughput of response time. The improvement of performance in a new system make the system will be effective. Performance can be measurement from throughput and response time where throughput is amount of work of which can done certain in a moment and response time is time mean which delay between two transactions.

Information ( information) : The improvement of information quality which presented.

Economy ( economic) : Increase the benefit of vs decreasing cost.

Control ( operation) : The improvement of control, detecting and improve;the mistake. To detection and repairing some faults and insincerity which possible happened.

Efficiency ( efficiency) : The improvement of operating efficiency. Efficiency related with how to use resource without doing extravagance.

Services ( service) : Increase the service of system.

System development principles:
1. System that developed management.
2. System that developed big capital investment.
3. System that developed to need one who educated.
4. Work stage and duties that must be done in course of system development (System Development Life Cycle).
5. System development process must not massage.
6. Don't be afraid cancel project.
7. Documentation existence for guide in system development.

Waterfall Model

Requirement : in process requirement this is systems analysis does need collecting process from customer and or top management either from aspect area also business strategy, towards system and or desirable application.
Design : in this stage us does systems analysis process, fitur that need, need from application that be made good to also the application. Beside that, here we also begin to make design plan from system, like interfaces delegation, the data structure, the architecture, and as it.

Implementation : implementation process has been continuation from where did we begin to implementation design that made to into program codes that be read by engine language.
Verification : process verification here same like testing process towards system and or application that made. This process focus in internal logic from application that made, as certain that any line coding checking. Beside that here we also have done testing process towards possibility towards errors from system that made.
Maintenance : process maintenance here be repair process and maintenance towards system that made. Repair process here done when application and or system that made to experience error after to customer so that must necessary repair process towards system and or caused by development towards an OS so that application must be repaired again to be update.

b. Iteratif Model

Initial planning : Be beginning planning process and or beginning ideas to make a system.
Planning : Planning here be a thinking that ripe towards system that be made.
Requirement : Same like in process requirement waterfall model, here systems analysis does need collecting process from customer and or management on towards system and or desirable application.
Analysis and design : In this stage us does systems analysis process, fitur everything that need, need from application that be made good to also the application. Beside that, here we also begin to make design plan from system, like interfaces delegation, the data structure, the architecture, and as it.
Implementation : Implementation process has been continuation from where did we begin to implementation the design that made to into program codes that be read by engine language.
Deployment : Process deployment here purpose has been distribution process towards system that made, in our meaning distributes before hand system to society before do testing so that we know our system deficit.
Testing : Process testing here we have done testing towards system and or application that made. This process focus in internal logic from application that made, ascertain that any line coding checking. Beside that here we also have done testing process towards possibility towards errors from system that made.
Evaluation : Process evaluation here be repair process, maintenance and renewal towards system that made. Repair process here done when application and or system that made to experience error after to customer so that must necessary repair process towards system. Maintenance process and renewal be done caused by development towards an OS so that application must be repaired again to update. In renewal process here will return to do process planning, data collecting (requirement), analysis system and design, implementation, deployment, testing and return again to evaluation. if there development again, so this cycle be repeated again.

Spiral Model

Spiral model explanation:

1. Determine objectives

in this process us will determine what will be made system, either from also output from it system.
2. Identify and resolve risk

here we do identification process, planning and analyze risks may be happen. In identification process and planning, we must define before hand resource, time precision, and other related information project with system that we shall make. While in risk analysis process here we do analysis towards risks may be happen, between management or technical.
3. Development and test

in process development and test this is us do engineering process, construction and testing towards system that be made. In engineering process and construction, we do process coding to make a application. While in testing, we do testing process towards system or application that we have made.
4. Plan the next iteration

here we do iteration process for plan next and or evaluation in the event of request from customer in order to change towards system or application.

3) Please explain approaches of developing a system

Approaches of developing a system

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

Classic approach vs. structured approach

Classic approach : is approach inside of developing a system that follow stages at system life cycle without supplied with tools and techniques.
Troubleshoots which can arise from this approach, such as:

a. Difficult development.
Classic approach less give tools and techniques insides develop system and finally software development process becoming not directional and difficult to be done by programmer.

b. Treatment cost or system maintenance will be more expensive.
The expensive treatment cost at classic approach caused system documentation that developed less complete and less structured.

c. Possibility of big error.
This approach doesn't prepare to manner systems analysis to do system testing, so that system errors possibility will be bigger.

d. System achievement less well guaranteed.
Because classic approach less involve system user in system development, so system user needs are less matching with the one which desirable and as finally system that applied less success.

e. Applying internal issue.
User will be startled and unaccustomed with new system suddenly introduced.

Structured approach : equipped with tools and techniques that wanted in system development, so that the end result from system which developed be got system the structure will be defined well and clear. In this approach, consumer involve from early to determine requirement of system and using tools like data of flow diagram

· Piecemeal approach vs. system approach

Piecemeal approach is system approach development that emphasized at one particular activity or certain application. This approach don't heed overall target.

System approach pays information system as integration unitary to each activity or the application. This approach also emphasized in overall goal achievement from organization, not only in that information target.

· Approach of bottom-up vs. approach of up-down

Bottom-Up Approach is begin from level under organization, that is from formulation requirements to handle transaction and climb level on with formulate information need based on transaction. Bottom-up approach is used in systems analysis steps, because of the pressure is data that be cultivated before, information that be produced will follow the data. Up-Down Approach on the contrary with bottom-up approach, this approach is begin from level up organization, that is begun with define target and organization policy. Step furthermore from this approach information need analysis. After information is determined, so process goes to transaction processing, that is determination output, input, data base, operating procedure and control. This approach be feature from structured approach. Top-down approach when used in systems analysis stage called also with term decision analysis, because that be pressure information that wanted for decision making by management beforehand, then data necessary cultivated to defined to follow information that wanted.

· Total-system approach vs. modular approach

Total-system approach to be approach develops system together according to comprehensive. This approach less synchronized for complex system, because will be difficult be developed. This approach be feature classic approaches.
Modular Approach tries to divide complex system to simple some part, so that system easier will be understood and developed. Furthermore consequence system can be developed of time that planned, easy understood by system user and easy to maintain. This approach be feature structured approaches.

· Great-loop approach vs. evolutionary approach

Great-loop approach applies change comprehensive according to together use sophisticated technology. This change contains many risks, because computer technology so great-loop. This approach also too expensive, because need investment at the same moment for all technology that used and difficult to developed because too complex. Evolutionary approach apply sophisticated technology just for applications that need that moment and then be developed for periods next based on technology development. This approach causes investment not too expensive and can follow fast technology development.

4) Please explain the meaning of methodology, method and algorithm

Methodologies is the methods which is used in science

Method [is] a way of systematic to do something

Algorithm [is] procedure sequence to solve a problem

5) Please explain the three classifications of development methodology

System Development Methodology
Methodology is methods unitary, procedures, job concepts, rules and postulates that used by a science, art or discipline the other. Method is a manner, systematic technique to does a certain. System development methodology means methods, procedures, job concepts, rules and postulates that be used to will develop information system. Algorithm is sequence procedure to break a problem.

Classification based on existing methodology can classified to be three, that is:

1. Functional decomposition methodologies.
This methodology emphasizeds in solution from system into subsystems smaller, so that easier to be understood, designed and applied. Belong this methodology, that is:

HIPO (Hierarchy plus Input-Proccess-Output)
Stepwise Refinement (SR) or Iterative Stepwise Refinement (ISR)
Information-hidding

2. Data-oriented methodologies.
This methodology will emphasized in characteristics from data that be processed. This methodology can be grouped to into two class, that is:

a. Data-flow oriented methodologies.
This methodology is based in solution from system intoes modules based on data element type and module logic behaviour insides system. Belong in this methodology, that is:
SADT (Structured Analysis and Design Techniques)
Composite design
Structured System Analysis and Design (SSAD)

b. Data structure oriented methodologies.
This methodology emphasizeds structure from input and output at system. Belong this methodology, that is:
JSD (Jakson's System Development)
W/O (Winner/Orr)

3. Prescriptive methodologies.
This methodology is usually is provided by software maker factory. Belong in this methodology, that is:

- ISDOS (Information System Design and Optimization System)

- PLEXSYS

- PRIDE

- SDM/70

6) Please mention tools for developing a system

Tools for developing a system

• Get graph form: HIPO, SADT, Jackson’s diagrams, etc.

• Tool that utilizes to design:

- Activity charting: figuring activity, example: chart's substituting, flowchart, etc.

- Layout charting: figuring layout

Personal relationship charting: figuring person relationship, example: organization chart, working distribution chart

7) Please explain techniques used in developing a system

There are the technique - used technique in developing a system

A. Management technique of project for schedule of project , example : cpm and of pert

B. Technique find fact to collect and determine data / fact 1. Interview 2. Observation

C. Technique analyse expense / benefit of cost-benefit and cost-effectiveness analysis

D. Technique to do the meeting

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

The differences of being a system analyst and a programmer and the knowledge a system analyst should posses.

System analyst studying problems and determine system user requirements to identify resolving.

Programmer writing program code bases engineering that made by analyst

• System analyst on call bridges distinctive happening science among system user and Data processing technology, computer and mathematics

• Science carries on business in common

• Quantitative method: regression, programming linear, etc. it

• Trouble-shooting membership

• Communication membership among person

• Membership builds relationship among person programmer

System Information Analyst and Design

2009-02-20T20:52:00.000-08:00

The Basic Concept of System and Information

The basic Concept of System

DEFINITION
The system is a group of procedure which each other is interconnected/ correlate one another for becoming or reaching a targetProcedure is a correct sequences of steps instruction which explain what must be done, who is doing, when done, and how do it.

OTHER MEANING OF SYSTEM
System is a group of elements which have interaction to reach specific purpose.

CHARACTERISTIC

Components
- Component which interacted for cooperation to form unity
- Supra system
Boundary of system
- Restrict system with other system / external environment of the system
External environmets of system
- Whatever beyond the boundary of system which influencing the operation of system
Interface
- The interface between one sub system with the other of sub system

Input
- Energy which entered into system, can in the form of treatment input and signal input.
Output
- The result from energy which have been processed and classified to become output, which have benefit from rest of dismissal.
Process

- To change input become output

Target (objective) / goal
- If the system do not have a target, therefor the operation system do not have benefit. The system have been told to succeed if have reached goal or target.

The Basis Concept of Information
The information likes the blood that flow on the body of an organization. The information’s source data. The data is describe the events and factual united.

information of cycle

The Quality of Information
Accurancy : The information must be free from the mistakes and doesn't drifftc of.
Timeliness : The information that come to receiver mayn’t late.
Relevant : That information has usual to user.

Value of Information
considered of 2 (two) factor, that is:
advantage and cost to get that information. Some information called to be have quality if the advantage of information more effective than the cost to get that information.
Usually the cost of value of information can connected by cost effectiveness analyst and cost benefit analyst.