Expert System

Expert system is a system was used to replace the role of an expert in providing consulting services to leaders in the organization. Ordinary employer employs expert staff who have to-an-expert in a particular area, egin the fields of finance ,marketing ,healthcare ,field production machinery ,and so forth . When the expert is difficult to obtain because there is little or too busy with other work, it needs an expert system to replace its role in the organization.

When an expert system to be built, then a software developer (software developer) to work together with an expert, these developers will conduct a series of question-answer (knowledge acquisition) to gather knowledge bases (knowledge base) the expert. Knowledge bases are then transferred to the base-knowledge expert system in terms of facts and rules. Then the developer to build an inference engine (inference engine) which is the decision maker in an expert system, collect information from users via frequently asked questions, and compare this information with the base-knowledge, then decide what should be informed to the user based on the data / information given.

When a user requires information from an expert system, then the inference engine will ask a series of questions to be answered by the user via a user-interface (user interface). The answers collected by the inference engine is then used to find information from the base-knowledge, this information is then forwarded to the user. If users want to know more details about the information obtained, it can be clarified through the facilities of explanatory (explanation facility).

Examples of expert system dialogue with its users is as follows:

System: Hello, I'm an fruit-expert, please answer my question, yes or no.

System: Is the color green?
User: No

System: What color is reddish purple?
User: Yes

System: Is the stem creeping?
User: Yes

System: Does the small round shape?
User: Yes

System: The fruit that you refer to is WINE

In order for this questioning can take place better then this expert system must have a base-knowledge as follows:

Apples: - the color yellow or red

- the trunk is a tree
- its shape is round

Wine: - reddish purple color

- stem creeping
- small round

Orange: - The color orange

- the trunk is a tree
- its shape is round

When the system is doing the question and answer with the answer Yes Users will create a basis to examine the knowledge base, for example in the example above is the input data (reddish purple, creeping, small round) and this data is matched to the characteristics of wine, then the answer of the system are: WINE.

Waterfall Model

Waterfall Model
This is classical model has systematic, in a series in build software. There are two descriptions from waterfall model. even if both use different phase names, but the main is same.
Phases in waterfall model (Pressman)

Phases in waterfall model (Sommerville)

Explanation
1. Requirements definition >>> gather need in its entirety then analyzed and be defined need everything that must be filled by software that be built. this phase must be done in its entirety to be able to produce complete design.
2. System and software design >>> design is done after need finished gatherred in its entirety. determine system architecture as a whole.
3. Implementation and unit testing >>> program design has translated into codes by using programming language that determined. program that built direct tested.
4. Integration and system testing >>> program units unification then tested as a whole (system testing). after system testing, software is sent to user.
5. Operation and maintenance >>> operate program in that area and do maintenance, like to setting or change because adaptation with situation actually. maintenance includes correction and various error yg tdk found in previous stages, repair on system unit implementation and system service development.
Weakness Of Waterfall Model
1. difficulty in contribute change after process is endured.
2. previous phase must complete and finished before do phase next.
Problem on waterfall model
1. difficult change is done because in character stiff.
2. because the stiff character, this model fit when need be be gatherred in its entirety so that change can be depressed as little as may be. but practically consumer/user that can give need in its entirety.
3. in general used for big system engineer where project is done at several places differ, and divided to be some part sub-proyek.

Software System

Software system

1. Explanation
Software system is a group program that written to serve the other programs. Software system must be installed before another software. Software system functioned to help computer do main operational task with make possible application software can operated. this system software consists of several programs that encoded by electronic. software system has function to regulate and controls hardware can do the task.

2. Kinds of software system
software system consist of 3 part, that is:

a. Programming Language
Is a language that used to write program computer, where give instruction to a computer to do to like computation and organizes current control deliver existing ware. The function is to changes architecture and algorithm that designed into format that can be run computer. For example : c++, pascal, c, java, phyton, visual basic, etc

b. Operating System
Operating system is a software that connect between hardware and brainware. function from system operation activate entire wares pair in computer so that each can mutual communicating. For example : Linux, windows, macintosh, FreeBSD, Unix, symbian, android, etc
c. Utility Software
Is a aid ware that help performance from a system operation.
Example : Tune Up Utility , C cleaner, etc

Software Engineering

Software Engineering

Software engineering is a discipline science that discuss about all aspect productions software, begin from early stage requirement capturing (user need analysis), specification (determine spesification from user need), design, coding, testing until system maintenance after used. Everything that relate to software production process, like: software project management, method determination and development process, staff determination, budget, time-table, quality, and training user. Software engineering is a
commands that used to processed information. can be in the form of program or procedure. Program is a commands that understand by computer. Procedure is a command that wanted by user in processed information (o’brien, 1999).
Two important system software kinds :

1. Operating system >>> be a liaison between user from computer with computer hardware.
2. Programming language >>> program that used to translate instructions that written in  programming language to engine so that acceptable and understood by computer.

Software characteristics

1. Software built and developed (engineered, musical note manufactures). differ from hardware (hardware), software be made with a planning then after so can be developed furthermore. cost to software be specific in development.
2. Software is never worn out (wear out) but deteriorate (deteriorate). software never worn out caused by treatment makes development pl to accustom with new need. but once software broken, so can not with other software, but must be done remaking for no access in software (differ from hardware).
3. Till now majority software stills made to follow order (custom-built)

Goal of software engineering

1. Low production cost
2. Tall program performance
3. Tall portability
4. Low treatment cost
5. Reliability system and
6. Capitulation on time

Software Application

1. System software
2. Real-time software
3. Business software
4. Engineering/scientefic software
5. Embedded software
6. PC software
7. AI software
8. Web Application