Minggu, Mei 03, 2009

ERD-NORMALIZATION

In the ADSI tasks given ERD similar to this, students are expected to be able to perform the following normalization of the ERD, and each table.


ERD is shown from above that the PEGAWAI entity,TANGGUNGAN and PROYEK, where they connected with the relations PUNYA. This is a little confusing where the cardinality is not specified to the PROYEK.
PROYEK I do not have a relationship with the TANGGUNGAN relationship can be removed. ERD is so similar to this one.



At first not allowed normalization of multivalued attributes and composite attributes.
In the ERD for the Employee entity there are composite attributes, therefore a decomposition similar to this



Entity to the other table still, no changes

On the relationship between the PEGAWAI-PROYEK, cardinality is many to many, so bring a new table that is KERJA

Here is a mapping

Mapping From this we can see in the PEGAWAI table appears PEGKONTROL attributes and NOBAG, this is obtained with the scale of relations where relations cardinality lower / lighter then primary key will be the foreign key in the table that cardinality more high / heavy. So also with the table-the table the other.

description:
1-N: the higher is N

Jumat, April 24, 2009

NORMALIZATION

DRAFT PROCESS DATABASE
• Gathering user needs / business
• Develop the ER model based on user needs / business
• Convert ER Model to set the relation (table)
• Normalization relations, to remove anomalies
• to implement the database for each table to create relationships that have been in the normalization

DATABASE NORMALIZATION
• Normalization process is the establishment of the database structure so that most of the ambiguity can be removed.
• The normalization stage starting from the light (1NF) to most stringent (5NF)
• Usually only up to the level of 3NF or BCNF because already sufficient to generate the table-a table of good quality.
• 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 described (Lossless-Join Decomposition). That is, after the table is described 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).
• Not 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
• Functional Dependency attributes describe the relationship in a relationship
• An attribute said functionally dependent on the other, if we use the value attribute to determine the value of the other attributes.
• Symbols used are --> to represent the functional dependency. --> reads determine the functional
• 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.
• Example:

Functional Dependency:
NRP --> Nama
Mata_Kuliah, NRP --> Nilai
Non Functional Dependency:
Mata_Kuliah--> NRP
NRP --> Milai
• Functional Dependency of the table value
Nrp --> Nama
Because for each value Nrp the same, then the value of the same name
(TMata_Kuliah, NRP) --> Nilai
Because the value of attributes depending on the study eye and NRP together. In another sense for the university and The NRP is the same, then the same value, because lecture The NRP is the key, and (is unique).
Mata_Kuliah -/-> NRP
NRP -/-> Nilai

FIRST NORMAL FORM - 1NF
A table on the form said to be normal if I did not reside in the un normalized form of a table, where there is a kind of field multiplication and field that allows a null (empty)

Not the allowed:
• Attribute values, many (Multi valued attributes).
• Attribute a composite or a combination of both.
So:
• Price is the domain attribute must be atomic rates
Eg Student Data as follows:

Or

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

Decomposition becomes:
• Student Table:

• Table Hobbies:


SECOND NORMAL FORM - 2NF
• The form of normal 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
• Functional dependence X-->Y if it is said of a remove attribute A from X means that Y is no longer dependent functional.
• Functional dependence X-->Y if it is said partial delete an attribute A from X means that Y is functionally dependent.
• The scheme in the form of the relation R 2NF if every non-primary key attribute A ÎR depend on the full primary key functional R.
• Example
The following table meet 1NF, 2NF, including but not

o Not fulfill 2NF, because (NIM, KodeMK) is regarded as the primary key:
NamaMhs -->(NIM, KodeMk)
Alamat-->(NIM, KodeMk)
Matakuliah-->(NIM, KodeMk)
SKS-->(NIM, KodeMk)
NilaiHuruf-->(NIM, KodeMk)
o Table in the decomposition should be some tables that are eligible 2NF
o Functional dependency as follows:
NilaiHuruf (fd1)-->(NIM, KodeMk)
(NamaMhs , Alamat) (fd2)-->NIM
(Matakuliah, SKS) (fd3)-->KodeMk
o So:
Value Table-->fd1 (NIM, KodeMk, NilaiHuruf)
Table Student-->fd2 (NIM, NamaMhs , Alamat)
Table Course-->fd3 (KoeMk, Matakuliah, SKS)

THIRD NORMAL FORM - 3NF

Third NORMAL FORM - 3NFBentuk normal 3NF met 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).

Example:
• Table the following students qualified 2NF, 3NF, but does not meet

• Because there are non-primary key attribute (namely, City and Provincial), which has a dependence on non-primary key attributes of (City, Province)the other (namely Poscode): Poscode
• So that the table should be in the decomposition:
• Students (NIM, NameofStudent, Road, Poscode)
o Poscode (Poscode, Province, City)

BOYCE-CODD NORMAL FORM (BNCF)
Boyce-Codd Normal Form constraint has a stronger form of the Normal third. To be BNCF, relations must be in the form of Normal onity and forced each of the attributes depends on the function in the super key attributes.
In the example below there is a relationship seminar, is the Primary Key NPM + Seminar.
Students may take one or two seminars. Each seminar requires 2 each of the students and led by one of the 2 seminar. Each leader can only take one seminar course. This is a sample:

Relations Seminar is a form of Third Normal, but not BCNF
Seminar Code because the function depends on the guide, if any guide can only teach a seminar. Seminar depend on one key attribute is not as super in terms of by BCNF. So
Seminar relations must be parsed into two namely:


NORMAL FORM FOURTH AND FIFTH
• Relations in fourth normal form (NF 4) if the relation in BCNF and dependency not contain many values. To remove the dependency of many values from a relation, we divide the relationship into two new relations. Each relation contains two attributes that have a lot of relationship value.
• Relations in fifth normal form (5NF) deal with the property called the join without any loss of information (lossless join). Fifth normal form (also called the 5 NF PJNF (projection join normal form). The case is very rare and appear difficult to detect in practice.

Sabtu, April 18, 2009

DATABASE AND ERD

DEFINITION DATABASE
•Set of data stored in the magnetic disk, optical disk or other secondary storage integrated collection of data-related data of an enterprise (company, government or private)
•Companies manufacturing production planning data, actual production data, data ordering materials, etc.

DATA BASE MANAGEMENT SYSTEM
•Bundles / database combined with software applications that are based database
•Programs are used for applications 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 the smallest pieces of data that contains the value 0 or 1
•Byte is the set of bit-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
•A relationship can also have attributes
•Example attributes:
teachers : NIP, name, address
book: id book, title, publisher

TYPE-TYPE ATTRIBUTE
•Single vs. Multi value
Single --> can be filled only at most one value
Multi value --> can be filled with more than one value with the same of type
•Atomic vs. Composition
Atomic --> can not be divided into the attributes of smaller
composition --> combination of several attributes of a smaller
•Derived Attribute
attribute value can be derived from other attribute values, expl -> age resulting from the date of birth attribute
•Null Value attribute
Attributes that have no value to a record
•Mandatory attribute Value
Attributes must have values

RECORD / TUPLE
It is a line of data in a relationship. Consist of collection of attribute-attribute-attribute where the attribute is to inform each other entity / relationship fully

ENTITY/ FILE
The file is a collection of similar records and have the same elements, the same attributes but different data value.

FILE TYPE
- Master File
- Transaction File
- File Report
- File History
- File Protection
- Job File

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

KEY DATA ELEMENT
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.

SPECIES OF KEY
•Super 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
Candidate 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. Unique
•Alternate Key
Alternate Key is an attribute of the candidate key is not selected to be primary key.
•Foreign 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 cardinalitas 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.

ERD (Entity Relationship Diagram)
ERD Is a network model which 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

ELEMENT-ELEMENT 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 relation.
•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
•Cardinalitas
tupel indicates the maximum number that can be relation with entities on the other entity

DEGREE OF RELATIONSHIP
•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.

CARDINALITY

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 of view .for an incident on the first entity can have any relationship with many incident on the second entity, if the one incident in which two entities can only have one with relation incident on the first entity.
Many To Many:
if any incident occurs in an entity has many relationships with other entities in the incident.

ER DIAGRAM NOTATION

Symbolic notation in the ER diagram is
Rectangle represent the collective entity
Circle represent the attributes
Rhomb collective relationships
Line as the link of relationships between the entity and the collective entity with collection of attribute

this is example for implementation

Sabtu, April 04, 2009

DATA FLOW DIAGRAM

DATA FLOW DIAGRAM
Can be called the Data Flow Diagram (DFD). Describe the distribution of the modules in the system to a smaller. Easy to understand the less the field to understand the computer system that will be done
CONTEXT DIAGRAM
Consists of a process and describe the scope of a system . It is the highest level of the DFD that describes the entire system to input and output of the system. The system is limited by Boundary (depicted by broken lines). No storage (storage)
ZERO DIAGRAM
Describe the process of the DFD. Provide views on the overall system in which, showing the main function or process that is, the flow of data and entity external. At this level of data storage possible. For processes that do not detail again on the next level then added the symbol '*' or 'P' at the end of the process. Input and output balance (balancing) between 0 to diagram context diagram should be maintained
DETAILED DIAGRAM
It is a process diagram that decipher what is in the diagram zero level or above. Numbering level in the DFD:

In the 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 process in the DFD must have a specification process. At the top level method is used to describe the process can use a sentence with descriptive. On a more detailed level, namely on the bottom (functional primitive) requires specification of a more structured. Specification process will be the guideline for the programmer to make this program (coding). Methods 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. with the notation described. External entity not part of the system including. Naming: (The name of the form of noun. Terminal may not have the same name unless the object is the same.
CASH DATA
It is a place where information flows. Described the straight line that connects the components of the system. Flow data is shown with the direction arrows and the name on the flow of data that flows. Flow data flow between processes, data storage and data flow indicates that the form of data input for the system. Guidelines of the name: ( Name of the flow of data that consists of some words associated with the flow lines connect. No flow data is the same name and the name should reflect its content. Flow of data that consists of several elements can be expressed with the group element. Avoid using the word 'data' and 'information' to give a name to the flow of data. T he extent possible the flow of data is complete). Terms of others: (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. Data flow into or out of data storage does not need to be given a name if: (Flow of data simple and easy to understand. Flow of data describing all the data items). No flow 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. The transform function of one or more of data input 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 is also often called bubble. Guidelines of the process: (Name of the process consists of a verb and noun, which reflects the function of the process. Do not use the process as part of the name of a bubble. There may be 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)
DATA STORAGE
Data storage is a storage place for data that exists in the system. Ilustratation 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: (The name should reflect the data storage. If the name more than one word must be marked with the number )
DFD Symbols

DATA DICTIONARY
Working 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 the analysis stage, the data dictionary is used as a means of communication between the systems analyst with the. 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: (Name of the data flow: must note that readers who need further explanation about a flow of data can find it easily. Other name of the data can be written when there is. The form of data: used to segment the data dictionary to use when designing the system. Flow data: indicates from which data flows and where the data. Description: provides an explanation about the meaning of the data flow
BALANCING IN DFD
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 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: (There should be a balance between input and output of one level and next level. 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. 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 of data from one process directly to the other without going through the process of saving data should / be avoided as much as possible

Kamis, Maret 26, 2009

OBSERVATION START, NEEDS ANALYSIS

INVESTIGATION SYSTEM CONCEPT
•Gaps differences (gaps) between the purpose of the system and actual system conditions.
•Reports detection problem is not really real: Destination is too ideal, and the lack of resources or attitudes, less accurate measurement system, a system already Purpose behind, The difference between the system and the system ideal while.
•Problem solving: Under the system that is running: a detailed investigation, Obtaining consensus that the ideal system, some alternative Developing, Selecting the best alternative.
•The goal is the investigation indicates the problem actually occurs.

CONSTRAINTS SYSTEM IN INVESTIGATION
In doing some investigation, the constraints that often appears is the time, cost, knowledge, political interference.

RECOMMENDATIONS
Results of the investigation is a recommendation that includes among others the following: Not to take any action -> not found any problems, Conducting system maintenance -> problems that small, capacity or skills of the user, modifications Consider the total system, Putting the problem to occur in development plan system is immediately done.

TRICK INVESTIGATION
•Required for Trick: Find all of the issues, Knowing the causes of the emergence of problems, Determining the right solution.
•Done so that all elements of the system can receive a quote a solution without disrupting their activities.
•Some of the tactics that can be done include: Listen to opinions of the system, Do not give the early breakthrough, Comparing the story of some people against the system the same case, the problem Note logical inconsistencies.

ENGINEERING INVESTIGATION
Can be done in two ways, namely: Direct (questionnaire, FAQ's, Observations), No Direct (Flow procedure, Learning documents, sample, Tabular).

WHEN THIS SYSTEM DESCRIPTION
Input, Output, File, Data Elements, Volume Transaction and document actions, data flow diagram.

NEEDS ANALYSIS
•Goals to be achieved: Explaining the complete system, describes the ideal information systems, information systems Bringing the ideal conditions at this time to pay attention to the constraints of resources, to give impetus to the confidence in the development of this system.
•Method: Interview,question fill, Observation, analysis procedure, Observation document.
•Constraints of resources: time, money, expertise, technology, External Factors.
•Document the needs analysis: analysis of referrals (Relationships with end users, the observation process, problems in data collection), Needs user (actual requirements, reporting requirements, training needs and the influence of the new system), system constraints (Explain the cost and time constraints, expertise, technology and external factors), the form document data collection instruments, statistical consensus, the logical flow of data and the physical, data elements in the initial data dictionary.

GENERATING SYSTEMS ALTERNATIVES
•How 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 systems, best alternative is applied wisely.
•Options Strategies: Distributed versus centralized processing; Changes centralized decision-making information from 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 into the file. Surround System of Strategy Development, Environmental around important strategy in the case of company takeovers because the information system of other companies may vary with the company at this time.
•Options Trick : 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 Real time record update, Sequential Vs Direct Access to records, Single Vs Multiple Users update of records. Output; Traditional Vs Turn Around Documents, Structured Vs Inquiry-based reports.

SELECTING THE PROPER SYSTEM
•Trick compare
System based on the comparison of costs and benefits relative. There are 3 ways a system said the system is superior to the other if: A has a lower cost of the benefit of both B and the same, have a cost lower than a B and a profit of more than B, A and B have the same cost advantage produced a lot more.
•Some Comparasi System Method: Break Even point Analyisis, 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, analysts give a description how the cost changes for the future and there are 3 models cost information system, namely Linear, and exponentially Step Function
•The cost of information system can occur only once and can also occur on an ongoing basis. Cost information system that occur only once the cost on time and development costs that occur during the development of the system. Cost information system that occur continuously among recuring cost and operational cost where the cost of this is the case when the operating system information every day.

FACTORS INTO INFORMATION SYSTEM
Qualitative factors that lead the performance of a good information system are: Reducing the level of error, Reducing the time to fix the error, Reducing the response time from the workstation alternatives, Accelerating the provision of information, Improving the security system, have update the source record is active, the user satisfaction Increase

FACTORS INTO CORPORATE STRATEGY
Customer satisfaction, increased sales Level, Commitment, and consumer vendor, product marketing information

PRESENTING LEARNING SYSTEM
Make short presentations, Reducing the technical detail explanation, Presenting clearly with visual aids, using a model If the tools used such as a laptop so that more informative, Emphasize the benefits of the proposed system with some alternative information that is appropriate conditions experienced by the company.

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

Sabtu, Maret 07, 2009

PUBLIC EVALUATION OF SYSTEM DEVELOPMENT

In development a system, this means compiling new system to replace system old ones. This is some factor influencing the importance of system innovated or changed, that is:

1.Problems
Problem can be in the form of:
a.Not all right
This matter can cause old system cannot operate as according to what expected, like:
•Which can insincerity result is not peaceful him properties of truth and company of data less well guaranted
•Mistake causing data not true and less well guaranted.
•Inefficient operation.
•Not adhere wisdom of management which have been specified.
b.Growth of Organization.
Growth organization cause have to compile of new system. This growth like requirement of information which will progressively wide, data-processing volume progressively mount, change principle of new accounting. All this result old system is not effective again.
2.Opportunities
Speed of time efficiency or information very determining success or failure of plan and strategy which have been made arrangements for to reach for existing opportunity
3.Directives
Compilation of new system earn also happened caused by instructions of head superior and or from outside organization, like for example regulation of government

TARGET OF SYSTEM DEVELOPMENT
•Solving problems
•Reach for opportunity.
•Fulfilling given instruction.

EXPECTATION AFTER NEW SYSTEM DEVELOPMENT.
•Performance
Increase of performance in new system should be effective. Performance can be calculate from the troughput and response time. Troughput are how many work that already done in a time. Response time are how many hour that you spand between two transaction or work plus with time response for respected that work.
•Information
Update the quality information.
•Economy
Upgrading about the important thing or profit the cost.
•Control
To the detection and repairing the mistake
•Efficiency
Upgrade the benefit or profit or lowering the cost. Upgrade about the operation efficiency. Efficient different with economy. So economy had related with how the source already in use with the minimum cost.
•Services
Upgrading the service that already giving from the system. For the example: Long time a go every body waiting for paying electricity tax, but the new system only pay the tax online it’s more easy.

PRINCIPLE SYSTEM DEVELOPMENT.
There are some principle in system development that is:
1.System for the management
After system have been developed, hence using information of system is management, so that system have to support requirement needed by management.
2.System are the big investor
Developed system require big capital fund. Capital investment have to consider two matter that is:
•All alternative which must the investigation of.
•best investment have to be valuable.
3.Developed system need one who is educated.
Human being represent especial factor which determine success or failure of a system, good in course of its development, its applying, and also in course of its operation. Hence from that needed one who is educated (work experience) using this system despitefully this people can give solution to problem of faced.
4.Step work and duties which must be done in course of development of system.
System Development Life Cycle generally show steps work and duty which must be done.
5.Process development of system do not have to massage
Steps can be done concurrently.
6.Do not fear to cancel project.
Project which have improper again, hence the project have to be discontinued or canceled. if this project remain to be continued hence will need expenditure of larger ones.
7.Documentation System.
Failure make documentation work is critical mistake which made by analyst of system. This documentation is made when process of development of system, because this documentation from result of activity every step of development of system. This documentation later used by communications materials between analyst of system with user of system and can be used to push involvement of user of system.

SYSTEM DEVELOPMENT OF MODEL.

1.Waterfall

Representing phase for the shake of phase passed by have to await to finish previous phase him and walk successive which started from requirements. This process represent determination requirement of the overall of system to application. This matter of vital importance, because this represent step early in make of information system. continued to process of design, Implementation, Verification, All functions of software have to be tried, to avoid problem, and result him have to really as according to previous requirement. And last phase is Maintenance. Conservancy a software very needed and represent phase requiring time which is extra because can happened development process, there are relevant problems, addition of function.

2.Iterative

This model same as like waterfall, only recur implementation. Visible at picture. First started from phase initial planning that is determination of planning which can use as plan early from information system to be made. Continue to next phase to implementation phase. Difference of model of iterative with system of waterfall that is can be cycled again to get better system.

3.Spiral

Model of Spiral divided to become six duty regional that is: Communications customer, Planning. Analysis risked. Engineer, Constructed and launching. Evaluation Customer
First trajectory of rotation yield growth of product specification. Used Next rotation to develop a prototype, and progressively develop more sophisticated software version. Each trajectory which passing planning area yield adjustment at planning of project. Expense and schedule accommodate pursuant to got feed back of customer evaluation. Project manager will add the amount of restating matching with the one which required.
Advantage : Can be accommodate software to can wear further, More suited for system development and big scale software, Developer and user earn easier comprehend risk, Using prototype as mechanism reduction of risk and in each situation in product evolution, Remain to follow steps in classic life cycle and input into framework of iterative, Requiring direct consideration to technical risk so that lessen risk before becoming the serious problem.

APPROACH OF DEVELOPMENT SYSTEM.

1.Classical/Traditional/conventional approach versus Structured approach
Classical/Traditional/conventional approach
Representing approach in system development follow steps in cycle life system without supplied with standard techniques and appliances. But will be able to emerge problem in this approach like: development of software will become difficultly, expense of treatment or conservancy of system will be more be costly, possibility of mistake of big system, efficacy of system less well guaranty, internal issue applying of system.
Structured approach
This approach provided with techniques and appliances which required in system development, so that end result of developed system become goodness.

2.Piecemeal approach versus System approach
Piecemeal approach
Represent approach of system development emphasizing at a just certain application or activity. Regardless of target overall of from organization. This approach only paying attention target of just application or activity
System approach
This approach also emphasize at goal achievement of overall from organization, do not only emphasizing at target of just information system

3.Down-top approach versus Top-down approach
Down-top approach
Started from level under organization that is operational level where transaction conducted. This is approach represent classic approach marking which often referred with core of data of analysis.
Top-down approach
Started from level of organization that is level plan of strategy. This approach started from defining target, analysis requirement of information, afterwards go down to transaction process that is determination of output, input, virgin bases, operating procedures and control. This approach represent marking of approach of structure which referred as with term of decision analysis.

4.Total-System approach versus Modular approach
Total-System approach
Representing approach developing system at a time by totally. This approach represent classic approach marking.
Modular approach
Modular approach try to solve complicated system become some part or simple module so that will be easy to comprehended and developed. Herewith system will be able to be developed nick of time which planned, easy to comprehend by user of system and easy to looked after. This approach represent marking of approach of structure.

5.Great loop approach versus Evolutionary approach
Great loop approach
Applying change by totally use sophisticated technology like computer. This approach using many fund because too costly. This approach also difficult to be developed because too complex
Evolutionary approach
Applying sophisticated technology for just certain applications. This approach develop to follow its requirement as according to growth of existing technology despitefully this approach cost effective and can keep abreast of technology which quickly.

METHODOLOGY DEVELOPMENT SYSTEM.

Methodologies is unity of methods, procedures and work concepts of used by science, artistic or other discipline.
Method is way of systematic to do something or way of to develop a[n information system.
Algorithm represent procedure sequences to solve problem

Classification Methodology Development System
•Decomposition methodologies Functional.
Emphasizing resolving of system become subsystem. Which including in it is HIPO, Stepwise refinement, iterative stepwise refinement, information hiding
•Methodologies Data-oriented.
Emphasizing at processed data characteristic
oData-flow oriented: modules according to data element type (SADT, Composite design, SSAD)
oData-structure oriented: input structure and output (JSD, W/O)
•Prescriptive
Which the included in this methodologies is ISDOS, PRIDE, SPECTRUM, SRES and SREM, etcetera

Appliance and technique in system development.
Used appliance generally in the form of graph like HIPO, DFD, structured chart, SADT, W/O, Jakson’s Diagram.
While used technique that is Technique management project : for schedule of project(CPM and PERT), Technique find fact : to collect and determine data ( Observation and interview), Technique cost analysis / benefit : and cost-benefit of cost-effectiveness analysis, Technique run meeting, Inspection technique.

Difference between Analyst System & Programmer.
System analyst: studying problems and determine requirement of user of system undertake to link difference of knowledge that happened between user of and system of programmer
Programmer: writing program code pursuant to designing to wake up made by analyst

Knowledge and skill required.
•Technological data processing, and computer of programmer
•Knowledge of business in general
•Quantitative Method : regresi, linear programming
•Skill of trouble-shooting
•Skill of communications between personnel
•Skill of construct relation between personnel

Jumat, Februari 20, 2009

Basic Concept of Information System Analysis and Design

Topics
• Elementary Concept ADSI
• Common Evaluation of System Development
• Policy and System Design
• Systems Analysis
• Desain System
• Selection System
• System Implementation
• Presentation of Project
Elementary Concept :
• What that System ?
• What is Information?
• What is Information System?
• Who got mixed up with Information System?
• Why need Information System?
• How to develop Information System?

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
• Components
Component which interact, work along to form one unity.
Supra System
• Boundary
Limiting system with other system / external environment
• Environment
Any beyond the bounds of from system which is influence system operation
• Interface
Link media between one system sub with other system sub
• Input
included Energi into system can in the form of treatment input and input of sinyal
• Output
Result of from processed energi and classified to become output which good for and rest of dismissal
• Process
Change input become output
• Target ( objective) / Target (goal)
Otherwise have the target of hence system operation there will be no utilizing of. System told to succeced when have hit target / its target

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.