PART VII: ANALYSIS AND DESIGN OF INFORMATION SYSTEM

NORMALIZATION

DATABASE DESIGN PROCESS (REVIEW)

• 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

Normalization are process of base structure forming data so a considerable part ambiguity can be removed. Normalization phase is begun of lightest phase (1NF) until tightest (5NF) Just usually comes up with level 3NF or BCNF because was enough is equal to result qualified tables goodness.

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 figuring relationship attributes in one relationship. An attribute is said functionally dependant on the other if we utilize to assess that attribute to determine the other attribute point.

Symbol that is utilized is for representing functional dependency. read functionally determines.

Notation: A --> B
A and B is attribute of one table. Matter functionally A determines B or B cling to A, if and only if available 2 data row with appreciative A same, therefore point B also same.

Notation: A -/-> B or A x -->B
Are opposite of previous notation.

Example FD (FUNCTIONAL DEPENDENCY)

Functional Dependency:

NRP --> Nama

Mata_Kuliah, NRP --> Nilai

Non Functional Dependency:

Mata_Kuliah --> NRP

NRP --> Nilai

Functional Dependency of point table

• NRP -->Nama

Because for each point same NRP, therefore Name point also same

• {Mata_kuliah, NRP} -->Nilai

Because attribute grade is depend to Mata_kuliah and NRP IS ala goes together. In other mean for Mata_kuliah and same NRP, therefore Point also with, since Mata_kuliah and NRP constitutes to key (get unique character).

• Mata_kuliah -->NRP

• NRP -->Nilai

FIRST NORMAL FORM (First is Normal Form - 1NF)

A table is said exist on normal form I if it don't exist on form un normalized table, where is happening multiplexing a sort field and enabling available field that null (empty).

Be not been allowed marks sense:

• Attribute that valuably there are many ( Multi valued attribute ).
• Attribute composite or combine of both.

So:

• domain price attribute shall constitute atomic price
• For example College Student Data as follows:

Or

Tables above are ineligible for 1NF

Decomposition becomes:

College Student table:

hobby table:

SECOND NORMAL FORM (second is Normal Form 2NF)

2NF normal form is accomplished in one table if have accomplished 1NF form, and all attribute besides primary key, as whole to have Functional Dependency on primary key. One table not accomplishes 2NF, if there is attribute which its dependency (Functional Dependency) just gets partial character only (just depend to one part of primary key.) If anything attribute that have no dependency for primary key, therefore that attribute has at move or is removed.

Functional dependency x --> Y. is said heaving full if erases A attribute of x matter y. no longer functional dependent. Functional dependency x --> Y. is said partial if erases A attribute of x matter y. still functional dependent. Relationship scheme r deep shaped 2NF if each attribute non primary key A Î R full dependent functionally on primary key R.

Example

Don't accomplish 2NF, since {NIM, KodeMk} one that is looked on as primary key whereas:

{NIM, KodeMk} --> NamaMhs

{NIM, KodeMk} --> Alamat

{NIM, KodeMk} --> Matakuliah

{NIM, KodeMk} --> Sks

{NIM, KodeMk} --> NilaiHuruf

That table needs at decomposition becomes many table that measures up 2NF

Functional dependency as follows:

• {NIM, KodeMk} --> NilaiHuruf (fd1)
• NIM --> {NamaMhs, Alamat} (fd2)
• KodeMk --> {Matakuliah, Sks} (fd3)

So

• fd1 (NIM, KodeMk, NilaiHuruf) --> Tabel Nilai
• fd2 (NIM, NamaMhs, Alamat) --> Tabel Mahasiswa
• fd3 (KodeMk, Matakuliah, Sks) --> Tabel MataKuliah

THIRD NORMAL FORM (Third is Normal Form 3NF)

3NF normal form is accomplished if have accomplished 2NF form, and if no attribute non primary key one that have dependency to attribute non primary key one that another( transitive dependency ).

Example

Following college student table this measures up 2NF, but doesn't accomplish 3NF.

Because is still exist attribute non primary key (namely Kota and Provinsi) one that have dependency to attribute non primary key another one (namely KodePos) :

KodePos --> {Kota, Provinsi}

So that table needs at decomposition becomes:

College student( NIM , NamaMhs, Jalan, KodePos)

KodePos( KodePos , Provinsi, Kota)

BOYCE-COD NORMAL FORM (BNCF)

Boyce-Cod Normal Form have stronger compulsion of shaped the third Normal first. To become BNCF, relationship shall in first normal form and each attribute is forced hinges on function on super key attribute.

On example hereunder exists seminar relationship, Primary key is NPM + seminar. Student may take one or two seminar. Each seminar needs 2 counselors and each student led by one of between 2 that seminar counselor. Each counselor just may take one seminar just. on this example NPM and seminar points out a Counselor.

Seminar Relationship form is shaped the third Normal Form, but don't BCNF because seminar Code is still hinge function on Counselor, if each Counselor gets to teach just one seminar. Dependent seminar on one attribute is not super key as presupposed one by BCNF. Therefore seminar relationship shall be broken down as two which is:

FOURTH NORMAL FORM AND FIFTH NORMAL FORM

Relationship in shaped fourth normal from (4 NF) if relationship in BCNF and not meaty dependency a lot of point. To remove dependency there are many point of one relationship, we divide relationship become two new relationships. Each relationship contains two attributes that have relationship a lot of points.

Relationship in shaped fifth normal form (5NF) get business with property is join the so called without marks sense information loss (lossless join). fifth normal form (5 NF also so-called PJNF (projection join is form normal). This case very rare appearance and hard to be detected practically.

REFERENCES:

Ngurah Agus Sanjaya ER, S.KOM, M.KOM, Slide presentation : Normalization

PART VI: ANALYSIS AND DESIGN OF INFORMATION SYSTEM

DATABASE AND ER-DIAGRAM

DEFINITION OF DATABASE
A database is a structured collection of records or data that is stored in a computer system. The structure is achieved by organizing the data according to a database model. The model in most common use today is the relational model. Other models such as the hierarchical model and the network model use a more explicit representation of relationships.

Coherent collection of mutually data get bearings of an enterprise (business, institution instance or private ).

• Manufacturing business: production planning data, current production data, ordering data significant, etc.
• Hospital: patient data, doctor, nurse, etc.

DATABASE MANAGEMENT SYSTEM
A DBMS is a set of software programs that controls the organization, storage, management, and retrieval of data in a database. DBMS are categorized according to their data structures or types. It is a set of prewritten programs that are used to store, update and retrieve a Database. The DBMS accepts requests for data from the application program and instructs the operating system to transfer the appropriate data. When a DBMS is used, information systems can be changed much more easily as the organization's information requirements change. New categories of data can be added to the database without disruption to the existing system.


BIT, BYTE, FIELD

• A bit is a binary digit, taking a value of either 0 or 1. Binary digits are a basic unit of information storage and communication in digital computing and digital information theory.
• A byte is a bulk of bit that a sort. Or a byte is an ordered collection of bits, with each bit denoting a single binary value of 1 or 0. The byte most often consists of 8 bits in modern systems.
• Field is a group byte’s that a sort, in data basis utilized by attribute terminology.

ATTRIBUTE/FIELD
Constituting character or characteristic of an entity that provide detail explanations about that entity. A relationship can also have attribute.
Attribute example:

• UNIVERSITY STUDENT: NIM, NAME, ADDRESS
• CAR: NOMOR_PLAT, COLOR, TYPE, CC

ATTRIBUTE TYPES

• Single vs multivalue

Single --> just can be filled at most one point
Multivalue --> can be filled by more than one point with same type of

• Atomic vs is composition

Atomic --> indiscrete into smaller attribute
Composition --> constituting affiliate of some attribute which smaller

• Derived Attribute

attribute that its point gets resultant of other attribute point, for example --> resulting age of date attribute comes into the world.

• Null Value Attribute

Attribute that have no point for a record

• Mandatory Value Attribute

Attribute who shall have point


RECORD/TUPLE
Constituting a data row in a relationship. Consisting of collection attribute's where that attribute interactions to inform entity / comprehensive relationships.


ENTITY/FILE
File constitutes collection from record what do a sort and to have same element, attribute is with but variably data value's.

File type
In application proceedings, file can at category as follows:

• Parented file
• Transactions file
• Write-up file
• History file
• Protecting file
• Job file

DOMAIN
Domain constitutes group of point that is let for lies deep one or more attribute. Each attribute in a relation data base is defined as a domain.


DATA ELEMENT KEY
key is record's element that is used to find record that on access time or can also be utilized to identify each entity / record / the line.


KEY TYPES

• Super key constitutes one or more attribute of a table applicable to identify entity / record of unique ala table (are not all attribute can be super key ).

• Candidate key is super keys with minimal attribute. Candidate key may not contain attribute of candidate's the other so key table definitely super key but was obviously contrariwise.

• Primary keys

One of attribute from candidate keys to get is chosen / is determined as primary keys with three criterions as follows:

• that key is more natural to been utilized as basis
• that key is simpler
• that key its uniqueness indemnity bond

Alternate keys is attribute from candidate keys that don't be chosen becomes primary key.

• Foreign keys to constitute bungling attribute which point for primary to key on the other table. Foreign keys will happen at one particular relationship which have cardinality one to many (one to there are many) or many to many (there are many to a lot of). Foreign key. usually do ever be placed on table that aims to go to a lot of.

• External keys to constitute a lexical attribute (or lexical gathering attribute) one that its point do ever identify one object instance.

ERD (ENTITY RELATIONSHIP DIAGRAM)
ERD is a model network which utilize wording that is kept in abstractive system. The difference among DFD and ERD.

• DFD constitutes a logistic network model that will be performed by system.
• ERD constitutes data network model that emphasizes on structure and relationship is data.

ERD ELEMENTS

• ENTITY

On ER Entity's diagram is figured with square form long. Entity is aught something in real system and also abstract where data is kept or where exists data.

• Relationship

On ER diagram relationship can be figured by one lozenges. Relationship is subjective artless one be become among entity. In a general way given by name by says basic job so making easy to do its relationship perusal.

• Relationship Degree

are total entity who participated in one relationship. Degree that frequent being used on ERD

• Attribute

are character or characteristic of every entity and also relationship

• Cardinality

pointing out record optimum that relations can with entity on entity another one.



DEGREE RELATIONSHIP

• Unary Relationship

are model relationship that happening among entity what do come from same entity set.

• Binary Relationship

are model relationship that happening among 2 entity.

• ternary Relationship

constituting relationship among instance of 3 entity types unilateral.



CARDINALITY
Available 3 cardinality relationships which is

• One to One: Subjective zoom one to one stated with one instance on entity first, just has one relationship with one instance on entity secondly conversely.

• One to Many or Many To One: Subjective zoom one to there are many is same with many to one pending of tenor which that relationship is seen. To one instance on entity first gets to have a lot of relationship with instance on entity secondly, if contrariwise one instance on entity just secondly gets to have relationship with one instance on entity is first.

• Many To Many: happening if each instance on one entity has a lot of relationship with instance on another entity.

EXAMPLE OF CARDINALITY





NOTATION (DIAGRAM E R)
Symbol notation diagrammatically ER is :

1. Length square declare for entity gathering
2. Circle declares for attribute
3. Rhomb declares for relationship gathering
4. Lining as connecting as among relationship gathering with entity gathering and Entity Gathering with its attribute.

References:
http://en.wikipedia.org/wiki/Database
http://en.wikipedia.org/wiki/Database_management_system
http://en.wikipedia.org/wiki/Bit
http://en.wikipedia.org/wiki/Byte
slide presentation "Database and ER-Diagram" by Agus Sanjaya ER, S.Kom, M.Kom

PART V: ANALYSIS AND DESIGN OF INFORMATION SYSTEM

DATA FLOW DIAGRAM (DFD)

DATA FLOW DIAGRAM (DFD)

Definition:

DFD often being utilized to figure a system has already there is or new system that will be developed logically without considering physical environment where the data flow (e.g. telephonic, letter etcetera) or physical environment where the will be save (e.g. file card, micro filhe, hard disk, tape, floppy disk, etc).

Data Flow Diagram (DFD) are constitute applicable assistive tool to figure information data flow and process of data, begun from data inclusion until results output .

DFD constitutes tool who will be utilized on systems developmental methodology which most structure (structured analysis and design).

There is even symbol Data Flow Diagrams:

1. External Entity
2. Process
3. Data flow
4. Data Storage

CONTEXT DIAGRAM

System Context Diagram are diagrams used in systems design to represent all external entities that may interact with a system. This diagram pictures the system at the center, with no details of its interior structure, surrounding by all its interacting systems, environment and activities. The objective of a system context diagram is to focus attention on external factors and events that should be considered in developing a complete set of system requirements and constraints.

System context diagram are related to Data Flow Diagram, and show the interactions between a system and other actors with which the system is designed to interface. System context diagrams can be helpful in understanding the context which the system will be part of.

Context diagrams are used early in a project to get agreement on the scope under investigation. Context diagrams are typically included in a requirements document. These diagrams must be read by all project stakeholders and thus should be written in plain language, so the stakeholders can understand items within the document.

ZERO DIAGRAM

• Figuring process from DFD
• Giving view thoroughly about handled system, pointing out function or aught process main, data flow and external entity
• On this level is enabled marks sense data storage
• To process that don't elaborated again on succeeding level therefore enhanced symbol ‘ * ’ or ‘ p ’ at the early process numbers
• Balancing input and output (balancing) among diagram 0 by context diagram shall be petted

DETAIL DIAGRAM

• Detail diagram that describes to process what aught diagrammatically zero or level on it
• Numbering level on DFD:

• In one advisable level has no is more than 7 processes and maximal 9, if more therefore has to be done by decomposition

SPECIFICATION OF PROCESS

1. Each process on DFD shall have process specification
2. On top level method that is utilized to figure process can by use of descriptive sentence

3. On more detail level which is on lowermost process (functional primitive) needing more specification most structure

4. Specification processes will be guidance divide programmer in makes program (coding)

5. Method that is utilized in specification of processes: b reakdown of process story type, decision table, decision tree

EXTERNAL ENTITY

Outer unity / system bounds( external entity / boundary), constituting unity at environment outer system can as person, organization or another system those are on environmentally extern will give input or accepts output of system. one that included outer unity amongst those:

1. An office, department or division in corporate but system open air, which is developed.
2. Person or a group person at organization but outside sys tem which being developed.
3. An organization or person of outside organization as e.g. subscription, provider.
4. Outdoor other information system, system being developed.
5. Original source of a transactions
6. Receiver a stop to a resulting reporting by system.

External entity symbol is:

Picture1. External entity notation at DFD

DATA FLOW

Symbol with the dart, where is data flow is flow between process, data trove. This data flow point out current of data who can as entry for system or result of system process and gets to get form as follows:

1. Form or document that utilized by firm
2. Resulting published reporting system
3. Output at computer screen
4. Entry for computer
5. Utterance communication
6. Letter or memo
7. Data that is read or is recorded at file
8. A noted stuffing on agenda book
9. Data transmission of a computer goes to other computer

Advisable data flow given by clear name and too have mean. Name of data flow is set inside and above its arrow line.

Picture2. Data flow that is flow from customer external entity go to process of customer order is by the name of customer order.

Inside draw data flow at DFD needs to be noticed many concepts that needs. This following is concept of data flow that needs to be noticed.

1. Concept packet of data, if two or more data are adrift from sources is same to the point same therefore have been looked on data flow one and only.

Example of Data flow which is false:

Example of Data Flow which is true:

If two data this will be handled by two disparate process, mean have a purpose that different, although its source of equal, therefore in draw as following been:

2. Diverging data flow, there is diverging data flow points out a number c.c. of data flow is same of same source to the point that different.

3. Converging data flow, data flow that converging points out many data flow that variably of source that variably jointly making for to the point same.

4. Source and to the effect concept data flow, All flow shall be resulted of is data process or making towards process (can one of or the two, which is process makes towards is not process or come from is not process to make towards process or comes from process and making towards process). This is important concept because flow is either one result's data process or will be utilized to do a process.

PROCESS

Process is activity or job that did by person, machine or computer of result a data flow that turns in at to process to been resulted data flow that will come out from process. Process function to transform one or many entry data become one or many output data correspond to desirable specification each process has one or many entries and resulting one or many outputs. Frequent process may be called by bubble

To physical data flow diagram (PDFD), process can be done by person, machine, or computer, meanwhile for logical flow's data diagram (LDFD), a process just point out process from computer. Process can be pointed out by symbol circle or with symbol length foursquare straightening with its dull angle.

Picture3. Process notation in DFD

Name application guidance processes:

• Name processes consisting of job and noun word that reflection that process function
• Never use word " processes "as part of name a bubble
• There are no several processes that have a same name
• Process shall numbered. Numbering of order possibility follow the flow or process of orders, however numbering order means not absolutely as process of order chronology.

DATA STORAGE

Data trove constitute trove of data who can as follows:

• A file or database at computer system
• An archives or manual note
• A data place box at someone table
• A manual referenced table
• An agenda or book

Data trove at DFD that in symbol can with a couple lining horizontal parallel that enclosed at one of its tip.

Picture4. Data Storage Symbol at DFD

1. A few things that needs to be noticed deep data trove depiction (source's data) : Just process just that in reference to data source, since one utilizes or revamp data at data source is a process.

2. Data flow that make towards data source of a process points out to process update to saved data at data source. Update can as added as or stored record or new document, deletion or takes document, and expurgation process.

3. Indigenous data flow of data source goes to a process point out that that process utilize data that is at data source.

4. To a process that does the two, which is utilizes and data source update can be chosen by use of one lining with dart two a purpose or utilizing two dart linings.

DFD SYMBOLS

DATA DICTIONARY

Data dictionary is a register organized element data with constant definition and according to system, so user and system analyst have same savvy about input, output, and data storage component. This data dictionary really to help the system analyst in define data that is flow in system, so definition is that data get compactly been done and most structure. Formation data dictionary is performed in analysis stage and design of a system.

On analysis stage, data dictionary constitute communication device among user and system analyst about data which is flow in system, which is about in going data to system and about information which needed by user. In the meantime, on lexical system scheme stage data is utilized to design input, reporting and database.

Formation data dictionary is gone upon path up data that exists on DFD. Groove data on DFD this gets global character, in mean just showing name grooves its data without showing structure of that data path. To showing structure of ala data path most inch therefore at forms data dictionary that is gone upon on data path in DFD.

Data dictionary load things as follows:

• Data flow name: shall on record that reader that require more explanation about a data flow can look for it squashy
• Alias: alias or other name of data gets to be written if available
• Data form: utilized to agglomerate data dictionary into its purpose one time of system scheme
• Data flow: showing of which data is flow and where data goes
• Explanation: giving explanation about meaning of data flow

BALANCING IN DFD

Data flow that turns in at and go out of one process have to equal data flow that turns in at and go out of details of process on level / level under it

1. Data streaming name which turn in at and go out of one process have with by the name of data flow that turns in at and go out of details of that process
2. Total and external entity of a process has to equal total and external entity of details of that process
3. Things who shall be noticed on DFD who has more than one level:

• Shall available input balance and output among one level and next level
• Balance among level 0 and level 1 is seen on input / output of data flow goes to or of terminal on level 0, meanwhile balance among level 1 and level 2 are seen on input / output of data flow goes to / of process that pertinent
• Data streaming name, storage data and terminal on every level shall same if its object same

PROHIBITION IN DFD

1. Data flow may not from external entity directing to external entity another without via a process

2. Data flow may not of direct data storage make towards external entity without via a process

3. Data flow may not of direct data storage wend another data trove without via a process

4. Data flow of one process directing to wend another process without via an advisable data storage / one can maybe be avoided

References:

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

HM, Jogiyanto. 2005. Analisis & Desain Sistem Informasi. Yogyakarta: ANDI.

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

http://id.wikipedia.org/wiki/Data_flow_diagram

http://mugianet.com/attachments/012_Data%20Flow%20Diagram.pdf