Kancutberbunga’s Blog

This image is provided for the ERD to normalization

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

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Database design process
• Gathering user needs / business
We must have a data user’s needs, which later will be the grip when designing the database. Needs that this will be the basis of the system that we created
• Develop the ER model based on user needs / business
Once we have all the data needs of users, then we can design ER models which later became the basis of data that will be built
• Convert ER Model to set the relation (table)
After have the framework of the ER model, we can enter data from the ER model to the table in the database that we design
• Normalization of relations, to remove anomalies
• to implement the database for each table to create relationships that are normalization

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.

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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.

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DATA FLOW DIAGRAM

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)

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With investigation, an analyst will be more problems and understand system flow more depth, although detect problems in the already known problem but still describe the size of the course. Many reports in the detection problem may not actually be real or can not be solved. This may be because:

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.

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Why need development if system?

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.

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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

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