From the image above, we can see the 2 errors are:
1.  nocardinality between BAGIAN entity and PROYEK entity
2.  no need relationship between TANGGUNGAN entity and PROYEK entity

NORMALIZATION OF MAPPING ABOVE :1NF/First Normal Form

At 1 NF

First Normal Form have the characteristics of each data file was formed in the flat, the data was in a record by one record and the value of the form field “atomic value”. There is no set of attributes that recurrent or re-valued attribute (multi value). Each field is only one definition, is not a collection of data that have meaning fork. Only one meaning only and is not a fraction also said the word so that means another.
First normal form does not permit:
- Composite attributes,
- Multi value attributes,
- Nested relations.

2NF/Second Normal Form

Second Normal Form has to meet criteria of First Normal Form. Non-key attributes must depend on the function key, so for the Second Normal form must be pre-determined keys field. The key field must be unique and may represent other attributes that become members

3NF/Third Normal Form

To become a Third Normal form of the relationship should be in the form of second normal and not all the attributes do not have a primary relationship transitive. This means every non-key attributes must depend only on the primary key completely. Second Normal form of the example above, including  of thrid Normal Because all the attributes that there depend on the full primer key.

Database normalization
• normalization process is the establishment of the database structure so that most of the ambiguity can lose . stage normalization phase starting from the light (1NF) to most stringent (5NF). The process of normalization should be done only up to 3NF. The process of 4NF and 5NF tend have a separate table that is too increasing the complexity and the query execution time, or often known by the term over normalization.

• Why do normalization?
- Optimization table structures
- Increase the speed
- Eliminate income data the same
- More efficient use of storage media
- Reduce redundancy
- Avoiding anomalies (insertion anomalies, deletion anomalies, update anomalies).
- Improved data integrity
• A table said good (efficient) or if the normal 3 to meet the following criteria:
- If there is decomposition (decomposition) table, it must be guaranteed safe decomposition (Lossless-Join Decomposition). That is, after the table is described / decomposition a new table-table, the table-table can generate a new table with the same exact.
- Maintain the functional dependence on the change data (Dependency preservation).
- No violate Boyce-Code Normal Form (BCNF)
• If the three criteria (BCNF) can not be met, then at least the table does not violate the Normal Form of the third stage (3rd Normal Form / 3NF).

Functional Dependency

notation: A –> B

A and B are attributes of a table. A means of determining the functional B or B depends on A, if and only if there are 2 rows of data with the same value of A, then B is also the same value

• notation: A –> B or A x–> B

• It is the opposite of the previous notation.

Sample table value:

• Nrp –> namaMhs

Because for each value Nrp the same, then the value of the same namaMhs

• {Namakul, NRP} –> NiHuruf

Because the Nihuruf of attributes depending on the NRP and namakul together. In another sense namakul for the NRP and the same, they also the same Nihiruf, because namakul and the NRP is a key (is unique).

• Mata_kuliah not –> NRP

• NRP not –> Nilai

Normal forms:

1. 1st Normal Form / 1NF
2. 2nd Normal Form / 2NF
3. 3rd Normal Form / 3NF
4. Boyce-Code Normal Form (BCNF)
5. 4th Normal Form / 4NF
6. 5th Normal Form / 5NF

First Normal Form – 1NF

· Normal form if it met a 1NF table does not have many valuable attributes (multivalued attribute), attribute composite or a combination of data in the same domain.

· Each attribute in the table must be atomic values (can not be divided-for more)

Ex student data as follows:

or

Table-the table above does not meet the requirements 1NF

decomposition to be:

Mahasiswa table:

Hobi Table:

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, if there are attributes that dependence (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

example:

Functional dependency like this:

{Mhs_nrp, mk_kode} –> nihuruf (fd1)

Mhs_nrp –> {mhs_nama, mhs_alamat} (fd2)

Mk_kode  –> {mk_nama, mk_sks} (fd3)

So:

fd1 (mhs_nrp, mk_kode, nihuruf) –> Nilai Table

fd2 (Mhs_nrp, mhs_nama, mhs_alamat) –> Mahasiswa Table

fd3 (mk_kode, mk_nama, mk_sks) –> MataKuliah Table

Third Normal Form – 3NF

Normal form 3NF fulfilled if the form meets 2NF, and if there are no non-primary key attribute that has a dependence on non-primary key attributes of the other (transitive dependencies).

Table following students eligible 2NF, 3NF, but does not meet

Because the table above there are still non-primary key attribute (ie, Kota and Provinsi), which has a dependence on non-primary key attributes of the other (ie KodePos), namely:

KodePos –> {Kota, Provinsi}

So that the table in the decomposition needs to be:

• Mahasiswa (NIM, NamaMhs, Jalan, KodePos)

– KodePos (KodePos, Provinsi, Kota)

Boyce-Code Normal Form (BCNF)

BCNF fulfilled in the form of a table, if for every functional dependency of each attribute or attribute combination in the form of: X –> Y and X is a super key

table must be based on functional decomposition of dependency, so that X becomes super-key of the table of decomposition

Each table in BCNF is 3NF. but will each 3NF not necessarily including A. The difference, for the functional dependency X –> A  not allow as part of a primary key.

4th Normal Form /4NF

For example, the table below do not meet 4NF:

]]> http://kancutberbunga.wordpress.com/2009/04/24/database-normalization/feed/ 0 kancutberbunga 1 li hi ma ho in 3nf hihi http://kancutberbunga.wordpress.com/2009/04/18/database-and-entity-relationship-diagram/ http://kancutberbunga.wordpress.com/2009/04/18/database-and-entity-relationship-diagram/#comments Sat, 18 Apr 2009 08:52:53 +0000 ngakan kutha http://kancutberbunga.wordpress.com/?p=76 ]]> Database and ERD (Entity Relationship Diagram)
definition of database
Some definitions from the Database in a number of perspectives:
• collective group data (records) that are organized each other in such a way that can later be used again quickly and easily.
• Collection of interrelated data stored together in such a way, and without repetition (redundancy) is not necessary, to meet various needs.
• Collection file / table / the related stored in electronic storage media.
• 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)
Example:
Manufacturing companies have production planning data, actual production data, data ordering materials, etc.
Hospitals have patient data, doctor, nurse, etc.
University faculty have the data, faculty, students, staff, etc.

DBMS (Database Management System)

DBMS software is designed to assist in the maintenance and
utility data collection in large numbers. DBMS can be the alternative
specifically to the use of applications, such as storing data in files and
write code for a specific application settings.

Benefits of Using DBMS
DMBS use to manage data have several advantages, namely:
Freedom of access to data and efficient

• reduction time application development

• integrity and data security

• Administrative uniformity data

• simultaneously access and improvements to the occurrence of crashes (crash of simultaneous process).

definition of bit, byte, and 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 / Field
It is the nature or characteristics of an entity that provides provide detail on these entities. within a relationship can also have attributes
Example attributes:
Lecturer: NIP, NAME, ADDRESS
STUDENTS: NIM, NAME, ADDRESS
CAR: NOMOR_PLAT, COLOR, TYPE, CC

Types of attributes
Single vs. multivalue
In the single type can only be filled at most only one nila
In the multivalue types can be filled with more than one value with the same type of
Atomic vs. composition
Atomic can not be divided into the attributes of smaller
The composition is a combination of several attributes of a smaller

Derived attribute
attribute value can be derived from the value of other attributes, such as age attributes resulting from the date of birth attribute
Null Value attribute
Attributes that have no value to a record
Mandatory attribute Value
Attribute must have a value, usually this is a primary key in an entity

RECORD / TUPLE
It is a line of data in a relationship, and consists of a set of attributes where the attribute-attribute-attribute is to inform each other entity / relationship fully

In the picture above is an example record NIM 9455500001, the name of Abdullah, the address of the feast, no4, this is a record

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 category as follows:
- Master File
- Transaction Files
- File Reports
- File History
- File Protection
- File Work
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
Key elements 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.

The types 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)
Cadidate Key is a super key with minimal attributes. Candidate must not contain a key attribute of the table so that the other 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 the unique
Alternate Key is an attribute of the candidate key is not selected to be primary key.
Foreign Key is any attribute that points to the primary key in another table. Foreign key will be going on a relationship that has cardinal one to many (one to many) or many to many (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 identify an object 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
DFD is a model of network functions that will be implemented by the system and the flow of data from the program
ERD is a model that emphasizes the network data on the structure and relationship data. ERD will be visible in the clear relationship between the data with other data.

The elements of 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.
􀂄 Example
Individuals 􀂋: employees, customers, students, distributor.
􀂋 Place: room, building, office, field, campus.
􀂋 Object: books, motorcycles, software packages, products
􀂋 event: registration, reservation, billing
􀂋 Concept: bank account, and qualification.

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 relation.

Relationship Degree
is the number of entities participating in a relationship. Degree which is often used in the ERD.
Attribute
It is the nature or characteristics of an entity that provides provide detail on these entities. within a relationship can also have attributes
Example
􀂋 Customer Attributes
No 􀂍 KTP / SIM
􀂍 Name
􀂍 Address

Cardinal
Figures show that the appearance of a large number of objects associated with the occurrence of the object on a relationship, a combination that may: (1:1, 1: N, M: N)

There are 3 relations cardinal, 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 seen . for an incident on the first entity can have any relationship with much 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 much have relationships with other entities in the incident.

- Unary Relationship
model is the relationship between the entity originating from the same entity set.
- Binary Relationship
model is the relationship between 2 entities.
- Ternary Relationship
is a relationship between the instance of 3 types of entities are unilateral.

Symbolic notation in the ER diagram is
Rectangle represent the collective entity
Circle represent the attributes
rhomb state collective relationships
Line as the set of relationships between the entity and the collective entity with attribute collective

DFD is a program with the algorithm using circle and arrow symbol to represent the flow of data in the design program. The use of notation in the data flow diagram is very helpful to understand a system. DFD will help the user understand the missing field to understand the computer system that will be done because DFD describes the flow of data in the system with a structured and clear.

CONTEXT DIAGRAM

Context diagram is the highest level of DFD consists of a process and describe the scope of a system. This process represents the entire system and also describes the relationship between input output system with the outside world. System is limited by Boundary (depicted by broken line) and the context diagram can not have storage (storage)

ZERO DIAGRAM

Describes the process of the DFD, and a description of the system and all kinds of processes in the system. Diagram giving zero overall view of the system in which, showing the main function or process that is, the flow of data and external entity and the possible existence of this level of data storage, or storage of data. Balance of input and output (balancing) between 0 to diagram context diagram should be maintained, meaning here between input and output from the context diagram, there must be also in the zero-level diagram

DETAILED DIAGRAM
Is a diagram that decipher what is the process in the diagram zero level or above. On this diagram, an explanation of the process above will be done in a play. In one level there should be no more than 7 units and the maximum of 9, when more should be done in the decomposition

rules on numbering DFD :

SPECIFICATION PROCESS

Each process in the DFD must have a specification of the process, here to explain the functioning of the process is in our system, the specification method used is the process of disintegration in the form of a sentence describe, decision table, decision tree. This specification will be a programmer for coding guidelines, Because in this specification clearly visible flow process, and steps in each process. At the top level method is used to describe the process can use a sentence with descriptive and in a more detailed level, namely on the bottom (functional primitive) require a more structured specification.

EXTERNAL ENTITY
Each system has certain limit system (Boundary) that a separate system with the outside environment. Something that is outside the system, but it provides data in the system or to provide data from the system this is called unity outside
1. Explained with the notation
2. External entity not part of the system including
3. Naming:
a. The name of the form of noun
b. Terminal may not have the same name except the same object

external entity symbols :

DATA FLOW

Data flow in DFD is given an arrow symbol. Flow of this data flow between processes, saving data and external entity. This data flow indicates flow of data from the data that can be entered to the system or the results of the processing system.
a. Guidelines of the name:
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
6. 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
7. Data flow into or out of data storage does not need to be given a name if:

7.1. The flow of data simple and easy to understand
7.2.Aliran data describe the entire data item

8. 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

data flow symbols :

PROCESS

The process is the work of a system, process the incoming data flow into outgoing data flow. In a process, there will be one or more and enter the result in one or several outputs. A process can occur when there is a input.
a. 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
4. 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

DFD SYMBOLS

DATA STORAGE

Savings is a savings of data from the data can be:
a. A database file
b. An archive
c. A table
Here, a process can take data from the savings of this data. explained with a pair of parallel lines or two lines with one of the side open.
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 processing. At analysis, the data dictionary is used as a means of communication between system analysts and users with the system design phase, the 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

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 it. This is not to be confusion in the process of the program, and the flow of data in accordance with the structure. Name of the flow of a process, must match the name of the details of the process flow diagram in the lower, the number and the name of an entity outside of the process, must be the same as the number and the name 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 the next level. Do not until the input and output level of 0 does not exist in the level 1.
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

1. Flow data may not be from outside the entity directly to other outside entities without going through a process
2. Flow data may not be from the savings directly to the data to outside entities without going through a process
3. Flow data may not be saving the data directly from the savings and other data without going through a process
4. Flow data from one process directly to the other without going through the process of saving data should / be avoided as much as possible

a. Goals that are too difficult or the ideal so that might not be reached.
b. The system can not be developed because of lack of resources, attitudes or
both.
c. Measurement system that is not accurate.
d. Statement of purpose of the system that is behind

e. The gap between the ideal system and the system at this time is while

In solving the problem, should provide an explanation of:
a. meaning condition of the system that runs through the investigation
in detail.
b. Getting a consensus that the ideal system.
c. Develop alternatives to reduce some of the differences gaps
between the ideal system with which the system is running.
d. Selecting the best alternative and sell it to management.
The objective of the investigation is to stabilize
or indicate a problem that actually occurs in addition as a way an analyst to understand the system in depth.

Constraint in Investigation System

In doing some investigation, there are obstacles or constraints that
will occur, among other issues:
a. Time
Analysts lack of resources time, so only do
part of the investigation. Usually time-related problems
cost is required.
b. Cost
Often the costs incurred related to the length of time for
investigation activities, so that management will give the limits of cost.
c. Knowledge
Manager information systems tend junior told analysts that have not been
have the technical expertise or knowledge is sufficient, so that will be
impact on the results of investigations that are less deep, mature or complete.
d. Politics
Management or the parties may distribute certain issues which
purpose is to restrict the investigation activities.
e. Interference
There are parties who try to intervene or
investigation in activities that will disrupt or cause
chaos.

Recommendation

Results of the investigation is a recommendation, which is one of them
as follows:
a. Does not take any action because it found no problems.
This can happen because the problem contrived so that when the investigation is done the problem-the problem does not happen or was not found.
b. Perform system maintenance for problems that small.
Maintenance of the system that made every day (short period) will be
help minimize the problem
c. Or improve skills in the run or the user
using information systems.
d. Consider modifications to the system in total, so the need to
thought to replace it with a new system.
e. Place going into the development plan system
which is done immediately.

Investigation tactic

a. listen, do not lecture.
If you know all the answers, you definitely will not conduct investigations.
So that in the investigation should provide enough time
management or for the user to explain in full and
systems analyst and clearly do not dominate the discussion.
b. Do not provide solutions to the initial problem. do not try to show ideas to solve the problem,
before the investigation is complete all the activities carried out, so avoid
solutions that part-part.
c. compare stories.
Different people mean different views of the same problem,
so the need to involve the supervisor and subordinate in the
view of the problem clearly and can be trusted.
d. Note the logical inconsistency problems

Inconsistency is the logical termination of the data flow where data
missing, or suddenly appear certain data. Some of the things that
dealing with this issue:
There are input data but no output (black hole).
* There is the output , but no input data (miracles).

Investigation Technique

Investigation techniques included:
a. Direct (internal) probes
Namely to find out directly what is happening in the environment
user.
There are three techniques for
conduct the investigation directly, with:
* Questionnaire
This technique is very appropriate, if in the investigation have constraints
and cost.The best time of the questionnaire is as a document that can show
differences that occurred in the respondents.
* Interview
These activities require time and special expertise. Not all people
able to interview successfully. Obstacles faced and the time is
special expertise.
* Observation
a powerful internal probe
Sit together with the system by making observations with the
question is more specific. Each question may
will be able to demonstrate problem-solving mysterious.

b. indirect (external) probes
Activities that can be done quickly and not visible from
operational personnel, so that they can know the outside or something
hidden from the user community. This activity will dominate
activities at the beginning of the SDLC, the internal probe to deepen.

* Flow of the procedure (procedure flow).
Use the system flowchart for the explanation of the way as the information operations procedures. If there is any problem in procedure, the problem may be
arise in the actual operations.
* Reviewing documents
Is to find and collect the documents necessary . Documents often caused problems.
* Sampling
Maybe you need information from the vendor that has been billing provide discounts at the time of payment, because the company lost money when the discount is not given when the delay of payment.You can involve the customer to get the payer information (although there are many transactions). Finally you can make list of sample data with the random selection for one last a week, select the 20 pages of daily transactions, select 5 items from each page are selected., record the information for each item and 5 calculate the average-Ra and variants to the sample-sample of all transactions payment occurs.
* Tabular
Also called the matrix, the check list to find discrepancies in the transaction flow

System Description at Moment

Determine the performance of the system at this time will have difficulty when
company does not have a standard performance measurement system.
Unfortunately, companies tend not to update documentation systems that are running. Therefore, analysts improve document system for investigating the problem.
Description of the system include a clear explanation at this time:
a. Inputs
b. Outputs
c. Files
d. Data elements
e. Volume of transactions and documents action

f. Data flow diagrams

Analysis Requirement

Requirement analysis phase is the intensive interaction between the analyst system with the user community the system (end-user), where the development team system shows the expertise to get the responses and confidence the user, so get a good participation.Is working hard to get agreement a user about their needs from an information system, as they may the failure of the previous information system.
In doing this step will be achieved 4 goals, namely:
a. Describe the system at this time in full.
b. Describes the ideal information system.
c. Bringing information system to the ideal conditions at this time with
attention to resource constraints.
d. Provide encouragement to the confidence of this team into the development
system.

Method needs analysis

Keep the selection method of collecting data for the right to system requirement. Methods are interviews, questionnaires, observation, analysis procedure, and document the survey. Each method will be described in depth as follows:

Interviews
1. Benefits of the method.
interviewer can measure the response through the questions and to adjust them
according to the situation that occurred.
Good for the problems that are not structured, such as why you
think this could happen?.
Demonstrating the effect of interviewer time.
create a high response since the preparation meeting.
2. Loss method.
• Requires time and cost is not small.
• Requires special training and experience of the interviewer.
• It is difficult to compare the interview reports as natural subjectivity.

Some important factors in both the interview, namely objektives,
audience, format, weighting and combining responses, and docummentation.

Questionnaires
1. Benefits of the method.
• Cheap and fast from the interviews.
• Not require a trained investigator (only one expert who
needed to design a questionnaire for end-user are selected.
• With easy-to minimize the cost for all end-user.
2. Loss method.
• Unable to create a specific question for the end-user.
• Analyst does not involve an impression so that can reveal personal
end-user.
• response to a low not because there is a strong encouragement for
return the questionnaire.
• Not be able to customize the questions to end-user specific.
Observation
1. Benefits of the method.
• Get the facts from the records of opinion.
• Not require construction of a question.
• Not disrupt or hide something (end-users do not know that they are observed).
• Analyst does not rely on verbal descriptions of end-users.
2. Loss method.
• If visible, analysts may change operation (end-user was observed).
• In the long term, the fact that in one observation may be
not appropriate (representative) in daily or weekly.

Procedure Analysis
1. Benefits of the method.
• Evaluation procedures can be done with the interferences is minimal and does not affect the operation.
• Procedure can flow into a structure checklist for make observations.
2. Loss method.
• procedures may not be complete and not up to date again.
• Learning the flow chart to document the time and expertise analyst.
Observations document
1. Benefits of the method.
• Minimize interruptions of operations functions.
• The beginning of the data element dictionary.
• Often, you can consider major procedural modifications.
2. Loss method.
• Requires enough time (there is a business organization in the
swamped with documents and reports).

Resource constraints

a. Time
Time constraints this can affect the analyst to consider the technology innovation that can not be operated in a short time. Therefore, the need to take enough time to have a respite so that they can make the most good alternative.

b. Money
The ideal information system would require the expensive cost, so that
requires adequate funding.
c. Expertise.
Staff information system may not have knowledge or experience
a significant problem telecommunications company mengkontrak consultants can add the ability to design. This will be the diperhadapkan
constraint costs incurred for energy consultants.
d. Technology.
Technology needs may become the main problem in supporting
working system, so the need to pay attention to the development of technology continues
again, the consequences of spending that occurred
e. Exsternal factors.
Many obstacles that come from outside of the design settings, such as prevention
use exotic technologies (of exotic technologies), to prevent
keep local data in a central database system, and so forth.

Generating Systems Alternatives

How do I approach the condition of the system at this time with the condition of the ideal system?
Creating an alternative to solve the problem of information system
Alternative is best applied wisely
Distributed versus centralized processing
Currently, there is a tendency changes occur centralized decision-making information from data processing to the end-user Decentralized responsibility center.in environment distribution process, end-user disconnect the equipment, and the implementation of priority development.
On the other there is a growing number of end-user to enter the computer world. They try the latest technology without considering the cost and risk. Without expertise, the system will be in a conservative environment

Integrated versus dispersed databases
When organizations use a database system spread, the system
consideration has the option of what files are included in the
database and the data are entered in the file. Integrated database
by the administrator maintain a database of all control data
storage, access and modification.

Surround strategy of system development
System development strategy is important because many companies
have a stack of the new system is designed and conditions
system that is currently being modified. This strategy allows the system designer
differences in language use of the program and run it on a computer
different for a full compatibility of the system. Strategy around the environment is very important in the problem corporate takeovers, in which one company to get the company
and information systems may not compatible with (different).

Tactics Options
Selection is done before the design operational
Designing Operational Options
Options can be grouped into the design
Input
Online Vs Off Line Data Entry
Keyed Vs Machine Readable Data Entry
Centralized Vs Decentralized Data Entry
Processing
Batch Vs Realtime record update
Sequential Vs Direct Access to records
Single Vs Multiple Users update of records
Output
Traditional Vs Turn Around Documents
Structured Inquiry Vs based reports

Comparison Tactics

System based on the comparison of costs and benefits relative. Cost is the demand for payment.benefit value or additional conditions as a result of the implementation of information systems. These matters include error rates, increasing sales (increased customer sales), and speed response time. The advantage is difficult to be measured because the qualitative (not just a number only descriptive). Increase customer satisfaction and reduce the resistance (end-user resistance) is a qualitative advantage. The advantage is the opportunity to increase (improve) the benefits the company.
There are three ways a system (A) can be more superior than the other system (B).
1. Have a lower cost than B, and both systems have
same benefits.
2. Have a lower cost than B, and A will also have the advantage
more than B.
3. A and B cost the same, but A has the advantage
more.

There are 4 methods used to compare two or more
information system, namely:
a. Break-even analysis (BEP)
b. Payback period
c. Discounted payback period
d. Internal rate of return (IRR).

Cost category
Basically the costs are divided into categories:
a. Hardware: Mainframe, minicomputers, microcomputers, and peripherals
equipment.
b. Software: systems, utilities, and application software.
c. People: analysts, programmers, operators, data entry personnel
d. Supplies: paper, tapes, disk
e. Telecommunications: modem, local area network cabling, multiplexors,
front-end processors
f. Physical site: air conditioning, Humidity control, security

Nature of costs
Comparing the cost of information systems through the life of the system, analysts prediction how the cost changes for the future. To do,there are three models operating cost information system, namely:
a. Linear.
b. Exponential.
c. Step function

Cost information system can occur once or continous.On-time costs, development costs are related to the development of the system, and recurring costs, operational costs are associated with the operating system information every day. The difference between one-time
(development) and recurring (operational costs) are often from the material.For example, the purchase of a computer is a one-time development system, while the rent is the same computer recurring operational cost.

The Information System

Some of the factors that lead qualitative performance information system that both:
a. Reduce the error level.
b. Reducing the time to fix the error.
c. Reduce the response time of interactive workstations.
d. Accelerate the provision of the report.
e. Improving the security system.
f. Propagate update the source record is active.
g. Increasing user satisfaction.
Several factors can be measured, but not in money.
There are factors the company strategy is as follows:
1. Customer satisfaction
Increase customer satisfaction will no doubt increase sales. As sales increase, however, difficult to predict and are quantitative.
2. Increase sales
Point of sales system (POS) from the free storage tasks record. Management expect sales staff devoted time to the business of marketing and sales is increasing. But sales will increase in difficulty to predict the money.
3. Consumer and vendor commitment
Company designing an online feedback system and allow consumers to directly access the system. Consumers are now locked on this system so that a commitment to faithful at the company. Consumer and vendor commitment difficult to predict.
4. Information product marketing.
Often, new information systems can be used by the others company .Like American Airline system provides information for marketing products in 1970, the company developed a system of booking and ticketing systems and marketing this service also used by other airlines, so that a product is profitable.

Here are some guidelines for presenting the study system successfully:
1. Presenting a short time to avoid exceeding
provided.
2. Reducing the technical explanation of detail may be minimal. More
both techniques are explained in detail to answer specific questions
of not requested.
3. Presented clearly, so that does not use the equipment visual.
4. If using a model (prototyping), take bring workstation
portable (laptop). Demonstration is more directly informative
and interesting than inactive visual aids.
5. Emphasize the benefits the proposed system with some information
alternative in accordance with the conditions experienced by the company.
Do not limit the other system information. Use financial values such as ROI (return on investment).

Go / No-go Decision

Top management must decide to continue (go) to develop a new information system or slow or does not approve the development of the system (no-go). If top-level management decisions, decided to development systems, information systems departments have begun the design process the next stage. If top management does not approve the proposed new information system, the systems development life cycle (SDLC) is stopped. Rarely as that. decision, top management to find a problem with the system study. The problem is not serious enough cause termination of project, but they re-work. This decision is the basis for the waterfall models of systems analysis. Model explains some of the stages of the repeated. Sometimes, the department of information systems decision making phases repeat before the present system study. With the alternative, the decision stage a repeat SDLC previously called or not

refernce:

http://kuliah.dinus.ac.id/ika/asi6.html

Development of system is to compile a new system and to replacing the old system or repair the old system. Development of system causing of several things that is :

1. Problem

a. The problem in old system causing the system do not function in an optimal fashion

b. Growth of organization causing development a new system is requirement of organization to information, data processing progressively mount while system old do not support the mentioned.

2. To reach for opportunity

With existence of system capable to handle requirement of information, data processing, hence availability of information providing various opportunity will progressively mount. Opportunity here for examples : opportunity of market, service to costumer.

3. Existence of instruction

Compilation a system will very affect by instruction factor from is external of organization, the example regulation of government

Things above also represent the intention of development a system. A system will be developed to overcome all problem of arising out, to get every existing opportunity, as well as fulfilling given instruction.

Development of new system which we can be measured from make up some factor, that are :

a. Performance

From system which we develop can be seen from moment performance efficiency before existence of new system, and which after new system there. Improvement of example, before there is new system, record keeping of sale conducted manually, binding report heaped in one rack. But report moment required, hence seeking will need the long time, here new system provide efficiency work earned handle some work at the same time (throughput). And with existing system assist organization give comments by request of customer (time response).

b. Information

Organization get all information accurately and quickly so that organization can use it as well as possible.

c. Economic

With existence of new system, company can economize expenditure. The example reduction of worker of manual in a few area capable to handle by system.

d. Control

From new system we earn to do operation to everything from within organization. The example in a supermarket, record keeping of goods can be controlled so that lessen opportunity the happening of which can insincerity harm our supermarket.

e. Efficient

New system is later expected can make company activity more efficiency not need the long time in doing a work

Service

With existence of new system, company can improve service to costumer.

PRINCIPLE SYSTEM DEVELOPMENT

Some principle which must be paid attention by developer of system is :

a. System for management

System developed pursuant to requirement of management, because later management which using many information of system.

b. System is big investment

Investigation of all alternative (minimization of opportunity missing cost) and Investment is the best.

c. System need one who is educated

Here not people have to with formal education, but earn is also conducted with grounding. Analyst of system have to understand system like what will be developed.

d. Job Step

Moment will conduct development of system, have to be made first a planning, what in it there are steps work development of system.

e. Development of system not have to be massaged

It’s intention here, moment conduct by job step, we don’t have to await one step finish, but also can be conduct concurrently.

f. Don’t fear to cancel project

If feeling system have improper again, we have to be coherent to cancel the project. So that later the expense of and drawn up by energy is cast way is not useless. This conducted with careful decision.

g. Documentation

Record keeping of moment making of system of vital importance because we earn to see growth of system which we make.

SYSTEM DEVELOPMENT LIFE CYCLE

model waterfall

In development of system there are model showing steps of system the developed. First model is model of waterfall, where here development of system started from planning of development of system, where this is step early from system, after planned later, then system in design, like designing of database, after designed by us step into implementation step of system to program and afterwards we will conduct verification. The last we have to conducted conservancy to developed system.

model iteratif

Model here much the same to with model of waterfall, only after system marketed, will be performed a test drive of system. Evaluation of test drive conducted to know weakness of system, if there are mistake, hence system will in requirements and analysis repeat

model spiral

a. Determine Objectives, in this process we must determine what will we do for the system.

b. Identity and Resolve Risk, we have identification process here, planning and analyze the risk that maybe happen on the system. We must define resource, time precision, and other related information project to the system that we want to create.

c. Development and Test, we do engineering process here, construction, and testing the system. We create the code to build the application.

d. Plan the Next Iteration, we do iteration process here for next plan and evaluate each request from customer in order to change the system or application.

APPROACH OF SYSTEM DEVELOPMENT

1. Classical approach vs structured approach (seen from used methodologies)

a. Classic approach

Steps in SDLC

Do not involve consumer, more is emphasizing of system analyst

Problems : difficult development, expense of costly treatment, possibility of big mistake, efficacy less well guarantied, applying internal issue

b. Approach structure

Customer involve from early to determine requirement of system

Using tools like data of flow diagram

2. Approach piecemeal vs system approach (seen from target to reach)

a. piecemeal Approach

Emphasizing at an activity or application

Heedless of entirety target

b. system Approach

See system as one intact unity

Emphasizing at goal achievement as a whole

3. bottom-up Approach vs top-down Approach (seen from determination of requirement of system)

a. bottom-up Approach

Started from bottom level that is operational

Representing classis approach marking

Recognized with term of data analysis

b. top-down Approach

Started from top level that is planning of strategy

Representing marking approach of structure

Recognized also with decision analysis

4. totally Approach vs moduler approach (seen from way developing it

a. totally system approach

Developing system at a time and totally

representing classic approach marking

b.  moduler Approach

Breaking complicated system become the parts of simple

Developed system become timely, easy to be comprehended and looked after

representing marking approach of structure

5. Great Lop Approach vs evolutionary approach

a. Great Lop Approach

Developing system at a time use sophisticated technology

High risk and finish many expanse

b. evolutionary Approach

Applying sophisticated technology for certain application

Developed to follow requirement

Cost effective and can keep abreast of technology

METHODELOGIES SYSTEM DEVELOPMENT

a. What is methodologies?

Methods and procedures which is used in science

b. What is method?

A way of systematic to do something

c. What is algorithm?

Medley of procedure to solve a problem

CLASSIFICATION METHODOLOGIES DEVELOPMENT

a. Functional decomposition

Emphasizing resolving of system become subsystem

b. Jackson’s diagram and others

c. Appliance using schema:

Charting activity : depicting activity, example : chart grant, flowchart, etc.

Charting layout : depicting arrange situation

Relationship charting personal: depicting personnel relation, example: chart organization, chart distribution working

TECHNIQUE SYSTEM DEVELOPMENT

a. Technique management of project for schedule of project example: CPM and PERT

b. Technique find fact to collect and determine data/ fact

Interview

Observation

c. Technique analysis expanse / benefit of cost-benefit and of cost-effectiveness analysis

d. Technique to run meeting

ANALYST AND PROGRAMMER

a. Analysis system : studying problems and determine requirement of user of system to identify resolving

b. Programmer : writing program code pursuant to designing to wake up made by analyst

c. Analyst system undertake to link difference of knowledge that happened between user and system of programmer

Programmer

1. Responsibility limited to making of program.

2. Knowledge enough limited to computer technology, computer system, needed programming languages and utilities.

3. Works of programmer is technical and have to precisely in making instructions of program.

4. Works of programmer of its relation only limited to humanity of programmer and system analyst

System Analyst

1. Responsibility not only at making of program, but at system as a whole.

2. broader knowledge, not only at computer technology but also at application area handled it

3. Work limited to trouble-shooting marginally.

4. Work of system analyst entangle with relation

Reff :  HM, Jogiyanto. Analisis & Desain Sistem Informasi. Yogyakarta: ANDI,2007.

Elementary concept of system

There are a lot of defining system, for computer science can be evaluated from congeniality of emphasis and procedure its element.

Seen from procedure

A system is a network from procedures which interaction to finish a certain target

Defining procedure

A Procedure is correct sequences from steps explaining what have to be done, who do, when do and how do

Defining system seen from element

System is corps of elements which have interaction to reach a target

Both definition above not interfere, different only way of its approach

Definition system seen from element is better than define system seen from procedure because in reality, a system can consist of some sub system. Sub System or components in a system cannot walk by self, surely have to interact to target reach.

System characteristic

System component is a system which consist of a number of component which interact and work along. Every sub system have the nature from system to run a certain function. A system can have a large ones system referred with system supra

Boundary

System boundary is area limiting between a system with radian or other system outside.

External environment system

Any exist in outside system boundary and have an effect on to system represent external environment system. External environment can profit or harm.

System Link

Link represent is a link media from one system sub to other system sub. Through this link enable resource emit a stream of between system sub.

Input

Input is entered energy into system. Input can in the form of maintenance input and signal input.

Maintenance input is entered energy to the system can operate. While signal input is energy processed to be got by output.

Output

Output is result of from processed energy and classified to become output which good for and rest of dismissal. Output can represent input for the other sub system or system supra.

Process

A system can have a part of processor to change input become output.

System Objective

A sure system have goal or objective. If a system do not have objective hence system operation there will be no utilizing of. So that objective from s system very determining once required by input is output and system to be yielded. A system told to succeed if exactly to the objective or goal.

Picture of characteristic a system

System Classification

System classified from some point, that are :

abstraction system is system which in the form of ideas which do not see physically. While physical system represent existing system physically.

Example from abstraction system : traditional system like subak

Example from physical system : computer system, networking system

natural system is system that happened through natural process, do not made by human being. While system made in human being represent made by system is human being mechanically.

Example from natural system : rain cycle, gravity system

Example from system made in human being : computer system, university system

System as certain system and system do not be certain. Certain system operate with behavior which have earned to be estimated. Computer system is example of certain system which is it behavior can be ascertained pursuant to run programs. While system do not be certain represent system which condition of its future can not be estimated by because containing probability element.

Example from certain system : information system, operation system

Example from system do not be certain : cashier system in super market

System as closed system and open system. Closed system represent system which do not correlate and do not have an effect on with external environment of him. While open system represent imbued with and corresponding system of external environment of him.

Elementary concept of information

What in fact that information ? so that of vital importance for a system? Information can be defined as processed data become more form good for and more meaning to accepting it.

Information cycle

Data is form which still raw not yet earned to tell a story many so that require to be processed is furthermore data processed to through a model to be yielded by information. Data processed to yield information a certain process model. Processed data through a model become information, receiver later then accept the information, making a decision and conduct action, which mean yield an other action to make a number of data return. The data will be arrested as input, re-processed pass a model forming a cycle.

Quality of information

Quality of from a information depended from 3 matter, that is:

Accurate

Accurate mean information have to free from mistake and do not bewilder, accurate also mean information must clear its meaning

Timely

Its meaning of incoming information at receiver may not lose time. Because information is the basis for in decision making

Relevant

Relevant mean that information have benefit for its usage

Information Value

Value of information determined from 2 matter that is expenses and benefit get it. An information told valuable if its benefit more effective compared to expense get it. However require to be paid attention that used information in a information system is generally used for a few usefulness.

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