Database Normalization

Normalization

• 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 rate

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.

• 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.

DATABASE AND ER-DIAGRAM

DATABASE AND ER-DIAGRAM

DATABASE

1. DATABASE DEFINITION

Definition of the database:

- A set of data stored in the magnetic disk, optical disk or other secondary storage

- Collection of integrated data-related data of an enterprise (company, government or private)

- A companies manufacturing production planning data, actual production data, data ordering materials, etc.

- A hospital patient data, doctor, nurse, etc.

2. DATABASE MANAGEMENT SYSTEM

- Collection / database combined with software applications that are based database

- Application programs are used to access and maintain databases

The main purpose DBMS is to provide an environment that is efficient and easy to use, withdrawal and storage of data and information

- BIT, BYTE, Field

- Bit is part of smallest data which contains value of 0 or 1

- Byte is a set of similar bits

- Field is a set of similar bytes, in the database used the term attribute

- Attribute/Field

- It is the nature or characteristics of an entity that provides provide detail on these entities

- A relationship can also have attributes

- Example of attributes:

- STUDENTS: NIM, NAME, ADDRESS

- CAR: CAR_NUMBER, COLOR, TYPE, CC

- TYPE-TYPE Attribute

- Single vs. multivalve

Single : can only be filled at most one value

Multi value : can be filled with more than one value with the same of type

- Atomic vs. composition

Atomic : cannot be divided into the attributes of smaller

Composition : combination of several attributes of a smaller

- Derived attribute

The attribute value can be derived from the value of other attributes, example : age can be derived resulting from the date of birth attributes

- Null Value attribute

Attributes that have no value to a record

- Mandatory attribute Value

Attributes must have values

3. RECORD / TUPLE

- It is a line of data in a relationship

- Consists of the set of attributes, the attributes relationship mutually to inform each other entity/full relationship

4. Entity / FILE

- File is a collection of similar records and have the same elements, the same attributes but different data value.

- File Type

In processing applications, files can categories, are:

- Master File

- Transaction Files

- File Reports

- File History

- File Protection

- File Work

5. DOMAIN

- Domain is the set of values that are allowed to reside in one or more attributes. Each attribute in a database relational is defined as a domain

6. Element KEY DATA

- Key is element of record which is used to find these records at the time of access, or can also be used to identify each entity/record/line

7. SPECIES OF KEY

- Super key is one or more attributes of a table that can be used to identify entity/record of the table are unique (not all attributes can be super key)

- Candidate Key is a super key with minimal attributes. Candidate must not contain a attribute of the another table so that the candidate key is certain super key but not necessarily vice versa.

- Primary Key

One of the key attributes of the candidate can be selected/specified a primary key with the three following criteria:

1. Key is more natural to use as reference

2. Key is more simple

3. Key is guaranteed unique

- Alternate Key is an attribute of the candidate key is not selected to be primary key.

- Foreign Key is any attribute those points to the primary key in another table. Foreign key will be going on a relationship that has cardinalities one to many or many to many. Foreign key is usually always put on the table that point to many.

- External Key is a lexical attribute or set of lexical attributes that values are always identifying an object instance.

ERD (Entity Relationship Diagram)

1. ERD DEFINITION

- ERD is a model of a network that uses word order is stored in the abstract system.

- Differences between the DFD and ERD

- DFD is a model of network functions that will be implemented by the system

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

2. Elements of the ERD

- Entity

In the ER Diagram Entity is described with the form of a rectangle. Entity is something that exists in the real system and the abstract where the data stored or where there are data.

- Relationship

ER diagram on the relationship can be described with a lozenge. Relationship is a natural relationship that occurs between entities. In general, the name given to the verb base making it easier to do the reading relationship

- Relationship Degree

Is the number of entities participating in a relationship. Degree which is often used in the ERD

- Attribute

Is the nature or characteristics of each entity and relationship

- Cardinalities

Indicates the maximum number of tupel that can be relation with entities on the other entity

- Unary Relationship

Is a model of the relationship between the entities originating from the same entity set

- Binary Relationship

Is a model of the relationship between 2 entities.

- Ternary Relationship

Is a relationship between the instances of 3 types of entities is unilateral.

3. Cardinality

There are 3 cardinalities relations, namely:

- One to One

Level one to one relationship with the one stated in the entities 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 much relationship is the same as the one to many depending on the direction from which look for the relationship. 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 relationship with the incident on the first entity.

- Many to many

If any incident occurs in an entity many have relationships with other entities in the incident.

4.

EXEMPLE OF CARDINALITY

5. Notation (E-R diagram)

Symbolic notation in the ER diagram is

1. Rectangle represents the collective entity

2. Circle represents the attributes

3. Belah Ketupat represents collective relationships

4. Link as the set of relationships between the collective relation with collective entity and the collective entity and with the attributes

Collective Entity

A key attribute of

Collective Relations

Link

DATA FLOW DIAGRAM

What is a data flow diagram?

A data flow diagram (DFD) is a graphical description of the ebb and flow of data in a given context. DFD allows you to identify the transformations that take place on data as it moves from input to Output in the system. (DFDs pre-date UML diagrams, but still have a complementary role to play in describing systems.)

Developing a data-flow diagram

Top-Down Approach

1. The system designer makes “a context level DFD” or Level 0, which shows the “interaction” (data flows) between “the system” (represented by one process) and “the system environment” (represented by terminators).

2. The system is “decomposed in lower-level DFD (Level 1)” into a set of “processes, data stores, and the data flows between these processes and data stores”.

3. Each process is then decomposed into an “even-lower-level diagram containing its subprocesses”.

4. This approach “then continues on the subsequent subprocesses”, until a necessary and sufficient level of detail is reached which is called the primitive process (aka chewable in one bite).

DFD is also a virtually designable diagram that technically or diagrammatically describes the inflow and outflow of data or information that is provided by the external entity.

Event Partitioning Approach

Event partitioning was described by Edward Yourdon in Just Enough Structured Analysis.^[4]

1. Construct detailed data-flow diagram.

1. The list of all events is made.

2. For each event a process is constructed.

3. Each process is linked (with incoming data flows) directly with other processes or via data stores, so that it has enough information to respond to a given event.

4. The reaction of each process to a given event is modeled by an outgoing data flow.

Data Flow Diagram (DFD)

- Describes the distribution of the system in to a smaller modules

- Easier for users with less understanding field of computer to understand the systems that will be done

Context Diagram

- Consists of a process and describe the scope of a system

- Is the highest level of the DFD that describes the entire of input in to system and output of the system

- System is limited by Boundary (depicted by broken lines)

- No storage

Zero Diagram

- Describes the process of the DFD

- Providing views on the overall system in which, showing the main process or function, the flow of data and entity external

- At this level of data storage possible

- To process that does not be detailed again on the next level then added to the symbol ‘*’ or ‘P’ at the end of the process

- Balance of input and output (balancing) between zero diagram with context diagram should be maintained

Detailed Diagram

- Is the diagrams that decompose a process that is in the diagram zero or level above

- Numbering level in the DFD:

1. Level Name : 0, Diagram Name : Context, Number of process : -

2. Level Name : 1, Diagram Name : Diagram 0, Number of process : 1.0, 2.0, 3.0, …

3. Level Name : 2, Diagram Name : Diagram 1.0, Number of process : 1.1, 1.2, 1.3, …

4. Level Name : 3, Diagram Name : Diagram 1.1, Number of process : 1.1.1, 1.1.2, …

- In one level there should be no more than 7 units and the maximum of 9, when more should be done in the decomposition

SPECIFICATION PROCESS

- Each of process in the DFD must have a specification process

- At the top level method is used to describe the process can use by a descriptive sentence

- At a level more detailed, namely on the process bottom (functional primitive) requires specification of a more structured

- Specification process will be the guideline for the programmer to make this program (coding)
Method used in the specification process : the process of disintegration in the form of a story, decision table, decision tree

ON FOREIGN

- Something that is outside the system, but it provides data in the system or to provide data from the system

- The symbol with the notation box

- External entity not part of the system including

- Naming:

1. The name of the terminal are noun

2. Terminal may not have the same name except the object are same

CASH DATA

- Is the place flow of information

- Depicted with the straight line that connects the components of the system

- Data flow direction is indicated with arrows and lines give the name on the flow of data that flows

Flow data flows between processes, data storage and indicates data flow form of data input for the system

- Guidelines of the naming:

1. Name of the flow of data that consists of some words associated with the flow lines connect

2. No flow data for the same and the name should reflect its content

3. The flow of data that consists of several elements can be expressed with the group element

4. Avoid using the word ‘data’ and ‘information’ to give a name to the flow of data

5. Wherever possible the complete flow of data is written

- Other provisions:

1. Name of the flow of data into a process may not be the same as the name of the data flow out of the process

2. Data flow into or out of data storage does not need to be given a name if:

§ The flow of data simple and easy to understand

§ Describes the data flow of all data items

There can be no flow of data from the terminal to the data storage, or vice versa because the terminal is not part of the system, the relationship with the terminal data storage must be through a process

PROCESS

- The process is what is done by the system

- The process can process data flows or data entry into the flow of data out

- Transform the process of working one or more of the input data into one or more of the output data in accordance with the desired specifications

- Each process has one or more inputs and produce one or more output

- The process also often called bubble

- Guidelines of the process:

1. Name of the process consists of a verb and noun, which reflects the function of the process

2. Do not use the process as part of the name of a bubble

3. May not have some process that has the same name

The process should be given a number. Order number wherever possible to follow the flow of the process or sequence, but the sequence number does not mean that the absolute is a process in chronological order

STORAGE DATA

- Data storage is a storage place for data that exists in the system

- Symbol with a pair of parallel lines or two lines with one side open side

- The process can retrieve data from or provide data to the database

- Guidelines of the name:

1. The name should reflect the data storage

2. When his name more than one word must be marked with the number

DATA DICTIONARY

- Work to help the system to interpret the application in detail and organize all elements of the data used in the system precisely so that the system analyst and have a basic understanding of the same input, output, storage and process

- At analysis, the data dictionary is used as a means of communication between the systems analyst with the users

- At the system design, data dictionary is used to design input, reports and databases

- Flow data on the global DAD, further details can be seen in the data dictionary

- Load the data dictionary as follows:

1. Name of data flow: must note that readers who need further explanation about a flow of data can find it easily

2. Alias: alias or other name of the data can be written when there is

3. Forms of data: used to segment the data dictionary to use when designing the system

4. Flow data: indicates from which data flows and where the data

5. Description: to give an explanation of the meaning of the data flow

BALANCING IN DFD

- The flow of data into and out of a process must be the same as the flow of data into and out of the details of the process on the level / levels below

- Name of the data flow into and out of the process must match the name of the flow of data into and out of the details of the process

- Number and the name of an entity outside the process must be equal to the number of names and entities outside of the details of the process

- The issues that must be considered in the DFD which have more than one level:

1. There must be a balance between input and output of one level and next level

2. Balance between level 0 and level 1 at the input / output of stream data to or from the terminal on level 0, while the balance between level 1 and level 2 is seen on the input / output of stream data to / from the process concerned

3. Name of the flow of data, data storage and terminals at each level must be the same if the same object

RESTRICTIONS IN DFD

- Flow data may not be from outside the entity directly to other outside entities without going through a process

- Flow data may not be from the savings directly to the data to outside entities without going through a process

- Flow data may not be saving the data directly from the savings and other data without going through a process

- Flow data from one process directly to the other without going through the process of saving data should / be avoided as much as possible

FIRST OBSERVATION, NEEDS ANALYSIS

INVESTIGATION SYSTEM CONCEPT

· Gap difference between the purpose of the system and actual system conditions

· Reports detection problem is not really real

§ Too ideal destination

§ Lack of resources and attitudes

§ Measurement system is less accurate

§ System that is the goal behind

The difference between the ideal system and the while system

· Problem solving:

§ investigation system that is running à investigation in detail

§ Getting a consensus that the ideal system

§ Developed several alternative

§ Selecting the best alternative

Destination of investigation à indicates the problem is actually happening

CONSTRAINTS IN SYSTEM INVESTIGATION

· Several problems that often appear are:

§ Time

§ Cost

§ Science

§ Politics

§ Intervention

RECOMMENDATIONS

· Results of the investigation is a recommendation that includes are:

§ Not to take any action à not found a problem à

§ Perform system maintenance à problems that small

§ Increasing the user ability or skills

§ Consider modifications to total system

§ Putting the problem to occur in the development plan system which immediately made

INVESTIGATION TACTICS

· Why we need tactics?

§ Find all problems

§ Knowing the causes of problems

§ Determine the appropriate solution

· Done so that all elements of the system can receive preferred solution without disrupting their activities

· Some of the tactics that can be done:

§ Listen to opinions of the performer system

§ Do not give the early breakthrough

§ Compare the stories of some of the performer system on the same cases

§ Note the logical inconsistency problem

INVESTIGATION TECHNICAL

· Direct:

§ The questionnaire

§ Frequently asked questions

§ Observations

· Not directly:

§ Flow procedure

§ Reviewing documents

§ Sample

§ Tabular

SYSTEM DESCRIPTION

§ Input

§ Output

§ File

§ Element data

§ Transaction volume and document action

§ Data flow diagram

NEEDS ANALYSIS

Stage of intensive interaction between the systems analyst with the end user where the development system team shows the expertise to get feedback and the user trust so get a good participation

· 4 PURPOSE THAT WANT ACHIEVED:

§ Explain the system completely

§ describe the ideal information system

§ Bring the ideal information system to conditions at this time with attention to resource constraints

§ Provide a stimulus to the user confidence in system development

· Method

§ FAQ

§ The questionnaire

§ Observation

§ Procedure analysis

§ Observation document

· RESOURCE CONSTRAINTS

§ Time

§ Money

§ Expertise

§ Technology

§ External factors

· Needs analysis document

§ Analysis guide: Relationships with end users, the observation process, problems in data collection

§ The user needs: The need actual, reporting requirements, training needs and the influence of the new system

§ System constraints: Explaining the cost and time constraints, expertise, technology, and external factors

§ Documents such as data collection instruments, statistical consensus, the logical flow of data and physical, data elements in the initial data dictionary

GENERATING SYSTEMS ALTERNATIVES

How do to approach the condition of the system at this time with the condition of the ideal system?

§ Create an alternative to solve the problem of information system

§ Alternative is best applied wisely

Options Strategies

§ Distributed versus centralized processing

Changes in decision-making of information from the centralized data processing to the end user decentralized responsibility center

§ Integrated versus dispersed database

System designer must consider the data are entered in the data base and the entrance to the file

§ Surround System Development Strategy of

The environmental strategy is important about in the case of company takeovers because the information system of other companies may vary with the company at this time.

SELECTING THE PROPER SYSTEM

· Compare tactics: systems based on the comparison of costs and benefits relative; There are 3 ways said system A system is superior to the other if:

§ A cost is lower than B, and the benefits of both

§ A cost is lower than B and A yield advantage of more than B

§ A and B have the same but the cost advantage generated a lot more.

· Some methods of Comparing System

§ Break Even point Analysis

§ Payback Period

§ Discounted payback period

§ Internal Rate of Return

· Cost categories

§ Hardware

§ Software

§ People

§ Suppliers

§ Telecommunications

§ Physical sites

· Cost details

Comparing the cost of information systems through the life of the system, analyst predict how cost changes for the future and there are 3 models cost information system, namely Linear, and exponentially Step Function

· Cost of information system can occur only once and can also occur on an ongoing basis.

§ Information system costs that occur once only cost that is on time and development costs that occur during the development of the system.

§ Cost information systems that occur on a continual basis are reccuring cost and operational cost where the cost of this is the case when the system information operating every day.

FACTORS INTO INFORMATION SYSTEM

Qualitative factors that head for the good performance of 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 the vendor’s commitment

§ Information marketing products

PRESENTING LEARNING SYSTEM

§ Make short presentations

§ Reduce the explanation of technical detail

§ Presenting clearly with visual aids

§ If using a model, using a tool such as a laptop so that more informative

§ Emphasize the benefits of the proposed of information system with some that there are alternative suitable conditions experienced by the company.

CONTINUING DECIDE OR NOT

§ If the company decided to develop the information system, the department will do the next process, namely Design System Process.

§ If on the contrary than the System Development Life Cycle (SDLC) will be terminated.

§ Often also will found problems with the system and the study and top management will usually ask for the fulfillment of the re-study system.

§ 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 phase or SDLC is not Go – No-Go Decision.

Development General Observation System

1. Importance development system

Development system means to arrange a new system to replace the old system in overall or to repair the system in used.

Any problems about the old system are :

1.1. That Troubleshoots Existence at Old One System

System are not operated on expectation

1.2. Organization Growth

Organization Growth to make arrange a new system. The old system are not effective. Because the old system can’t give information needed.

1.3. To reach opportunities

To competitive, the company must to used a technology. If not, the opportunity to reached by the competitor. The opportunities are market opportunity, costumer services, and so on.

1.4. Directives

To arrange a new system can be happen by instructions from director and external organization.

Any indicator can be used to saw the system need to developed is:

· Complain from the costumer

· Often delayed to send goods

· Wrong content report

· Not good files

· And so on

With to developed the new system, to hoped increased in that system. The increased are: PIECES (Performance, Information, Economy, Control, Eficiency and Services)

· Performance : increasing performance work and result

· Information : increasing the quality of information saw

· Economy : increasing out come benefit

· Control : increasing of control to detect any mistake/dishonest

· Efficiency : increasing the operation of efficiency (output/input)

· Services : increasing services to give by the system

2. The principle of development system

2. 1. System to developed for management

System must support the needed management

2.2. Development system is a big capital investment

The information system will be make need a lot of capital, especially to use the high technology.

Capital investment must to consider two things, are:

a. Investigate all of alternative

investigate all of alternative to establish thee best alternative

b. the investment must valued

2.3. A system to developed needed educational person

2.4. Step/process to development system

Before to develop system, must to make a work schedule there for a process of development system finished according to the planning.

2.5. The process of development system are not chronological

the process of development system to do by all together.

2.6. Don’t be afraid to cancel the project

The decision to continues or cancel a project must evaluated in carefully.

2.7. Tthe documentation must oriented on development system

3. Life Cycle development system

3.1. Regulatin and Planning of System (The Beginning pProject System)

3.2. System Analysis (Development System)

3.3. The General of Design System (Development System)

3.4. The Detail of Design System (Development System)

3.5. The Selection System (Development System)

3.6. The Implementation System (Development System)

3.7. The Maintenance System (The Management System)

4. The Development System Approached

Any approached to development system, are:

4.1. Classical approached vs. Structured approached (look by development method)

4.2. Piecemeal approached vs. System approached (look by development target)

4.3.Bottom-up approach vs. top-down approach (look by needed system method)

4.4. Total System approach vs. modular approach (look by development method)

4.5. Great loop approach vs. evolutionary approach (look by technology in used)

Classical Approach

Classical approach is approach insides system development that follow stages at system life cycle without supplied with tools and techniques.
Troubleshoots that can emerge from approach classic, that is:

1. Software development will be difficult.
Classical approach less give tools and techniques insides develop system and as finally software development process becoming not directional and difficult to done by programmer.
2. Treatment cost or system maintenance will be more expensive.
The expensive treatment cost at classical approach caused system documentation that developed less complete and less structured.
3. Big error possibility system.
System not test during the development stage is principal source from system errors. Classical approach doesn’t prepare to manner systems analysis to do testing system, so that system errors possibility will be bigger.
4. System success less well guaranted.
Emphasis from classical approach work from system developers staffs, not in system user. Because classical 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.
5. System applications internal issue.
Because system user involvement under communication in system development stage, so only will know only in stage will applied. As finally system user will be startled and unaccustomed with bew system suddenly introduced.

1. Structured Approach

Structured approach equiped with tools and techniques that wanted in system development, so that end result from system that developed be got system the structure will be defined well and clear.

2.Piecemeal Approach Vs System Approach

Piecemeal approach
Piecemeal approach be to system approach development that emphasized at one particular activity or certain application. Activity that chosen, developed regardless of the position at information system or regardless of overall target from organization.

System approach

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

3. Bottom-Up Approach vs Top-Down Approach

Bottom-Up Approach

This approach begun from level under organization, that is begun from needs formulation to handle transaction and climb level on with formulate information need based on transaction. This approach also be feature classical approaches. Bottom-up approach is used in systems analysis stage is called also with data analysis, because that be pressure data that be cultivated before hand, information that be produced to follow to follow the data.

Top-Down Approach

This approach on the contrary begun from level on organization, that is begun with define target and organization policy. Step furthermore from this approach melakukannya 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 desicion 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.

4. Total-System Approach vs Modular Approach

Total-System Approach

Total-system approach to be approach develop 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

This approach try to divide complex system to simple some part, so that system easier will be understood and developed. Furthermore consequence system can be developed bick of time that planned, easy understood by system user and easy to maintained. This approach be feature structured approaches.

5. Great-Loop Approach vs Evolutionary Approaches

Great-Loop Approach

This approach apply 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

This 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.

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.

2. Data-oriented methodologies.

a. Data-flow oriented methodologies.
b. Data structure oriented methodologies.

3. Prescriptive methodologies.

Basic Concept of Information Analysis and Design

Before studying what that Information Systems Analysis and Design, first we have to know what that system and what that information.

WHAT IS SYSTEM?

There are two approaching to definition of system:

1. Definition of system based on approach of procedure
According to this approach, system interpreted by as a working network from procedures which is interaction and work along to finish a specific-purpose or goal. A procedure is a correct sequences of instruction steps explaining what have to be done, who have to do, when have to be done and how to do that.

2. Definition of system based on approach of element
According to this approach the definition of system is a set of elements which is have interaction to reach specific-purpose or goal.

CHARACTERISTIC OF SYSTEM

Characteristic a system can be explained as follows:

1. Components
Consist of a number of components which interact, what each other working along to form an unity. The example is Supra System that is a larger ones system.

2. Boundary
A system has a boundary to limiting system with environmental or other system outside its.

3. Environments
Environment is a media link between a subsystem with other subsystem.

4. Input
Entered energy into system can in the form of treatment input and signal input. The treatment input is entered energy system to can walk. While signal input is energy which in process to yield output.

5. Output
The result from processed energy and classified is become an output which good for and rest of dismissal.

6. Process
Process is the change an input become output.

7. Target (objective)/goal
Otherwise have the target then system operation there will be no utilizing of. The system is told succeed if it has reach the target/its goal.

The Classification Of System

a. Deterministic System
The Certain system operate with behaviour which have earned can be predicted, interaction between its sharess can be detected categorically so that its output can be forecasted. for example of : Computer programe, executing precisely as according to its instruction network. System of pay, and others.

b. Probabilistic System
The System which is input and its process can be defined, but yielded output cannot be determined categorically; ( always there is a little mistake / deviation to forecast of the way system). for Example : marketing system)

c. Open System
The system that relation and effect external environment .This system accept input and yield output for external environment / the other sub system, so that have good operation system. This system tend to measure up to adaptation, can adapt to its environment so that can continue its.

d. Closed System
The System Physical where the process that happened do not experience of transfer of items, information or energy with environment outside system. This system work automatically without existence of interfere in of external side of it.

e. Relatively Closed System
The closed System but doesn’t closed at all to accept other influences. This system in its operation can accept influence from outside which have been defined in certain boundarys.

f. Artificial System
The System imitating occurence in system. This system is formed pursuant to occurence in nature where human being unable to do it. Equally imitat exist in nature.

g. Natural System
The natural System is occurence in nature. for Example of : sea, solar system and others.

h. Manned System
The System explanations of behaviour covering human being taking part in. This system can be depicted in way of as follows:
The System of Human being focus the relations between human being
The System of Human being – Machine, System which involve machine to a target
The Machine System, automatic system where human being have duty to start and finish system, meanwhile human being entangled also to monitor system.

Information
Data is fact. Information is data that processed become better form and more meaning to accept it. If data is not useful to accept it so the data cannot be referred as by information.

QUALITY OF INFORMATION

To get information with quality, then information must have:

*Accurately
Information free from mistakes and doesn’t deflect or mislead

*Punctually
Incoming information at receiver may not lose time

*Relevantly
Information is have benefit for its usage.

Information will be valuable if big added significance of expense get it

Hello world!

Welcome to WordPress.com. This is your first post. Edit or delete it and start blogging!