Structured Systems Analysis and Design Method. SSADM with ConceptDraw DIAGRAM
Structured Systems Analysis and Design Method (SSADM) is the method which is used at projecting and analysis of information systems. This method was developed for government of Great Britain in the beginning of 80th of the past century. It was accepted as the national standard of Great Britain for information systems development in 1993. Thus SSADM usage is expedient for those who work with governmental organizations as this method is a standard for these organizations.
SSADM is based on the data flow diagrams. At the early stages of projecting at description of models (functional, informational and event-trigger) the top-down method is used.
At the description of data flows out of the system and into the system DFD, which denote boundaries of the system, are used.
At the description of data models LDS (Logical Data Structure) diagrams are used. LDS describes which data the system operates with. It is created for existing system and is added at the development of the new one.
For modelling events, happened in the system, ELN (Entity Life History) diagrams are used. These diagrams support states indications and the possibility of description not only consecutive but parallel or reiterative events and also description of the choice of events course.
ELN describes how data change in the system in the course of time at different variants of events.
Thus, the most important SSADM elements are flows modelling with the help of DFD, data logic modelling with the help of LDS and description of entities behavior.
Analysis, projecting and documenting of information system accordingly to SSADM involves 6 main stages.
Each stage is divided into several steps, which define tasks that should be fulfilled at the given stage. The system is studied for getting system requirements. Detailed project is created on the logic level and then transformed into physical project.
- Analysis of the existing system or estimation of practicability. It involves the analysis of the existing system and creation of DFD for visualization of known problems and system description. If the system is developed from the beginning than the projecting starts from definition of new system requirements.
- Requirements definition. On the basis of available data about the system new functions, which the system must execute are defined. Also boundaries of the future system and data which will be processed by the system are defined. Infological model of requirements is constructed.
- Definition of technical requirements and device equipment cost. Definition of the expected profit with the introduction of new functions.
- Development of logical data model. Specification of the list of functional requirements. After development of the logical project the adding of new requirements on SSADM is forbidden. Only correction of the existing requirements, their specification and concrete definition are allowed.
- Projecting of logical requirements. Specification of requirements.
- Physical projecting. Physical information model and specification to program elements are developed and optimized. Specifications to program elements are specified and documentation is drawn up.
The advantages of SSADM are the precise definition and support of so-called “non functional requirements”. Such requirements define the level of the quality with which the system must execute its functions. For example, access limitations, the mean time of lifelength to denial, time of the response, safety requirements, etc.
In comparison with other methods of information system projecting, particularly with E. Yordon and A. Young methods, SSADM is characterized with presence of clear consecution of steps at projecting.
Pic.1. Structured Systems Analysis and Design Method solution
The following features make ConceptDraw DIAGRAM the best Data Flow Diagram software:
- You don't need to be an artist to draw professional looking diagrams in a few minutes.
- Large quantity of ready-to-use vector objects makes your drawing diagrams quick and easy.
- Great number of predesigned templates and samples give you the good start for your own diagrams.
- ConceptDraw DIAGRAM provides you the possibility to use the grid, rules and guides. You can easily rotate, group, align, arrange the objects, use different fonts and colors to make your diagram exceptionally looking.
- All ConceptDraw DIAGRAM documents are vector graphic files and are available for reviewing, modifying, and converting to a variety of formats: image, HTML, PDF file, MS PowerPoint Presentation, Adobe Flash, MS Visio.
- Using ConceptDraw STORE you can navigate through ConceptDraw Solution Park, managing downloads and updates. You can access libraries, templates and samples directly from the ConceptDraw STORE.
- If you have any questions, our free of charge support is always ready to come to your aid.
TEN RELATED HOW TO's:
In ConceptDraw DIAGRAM it really is sp simple to draw even the most complex cross-functional flowcharts. Use the RapidDraw technology and Cross-Functional libraries in ConceptDraw DIAGRAM for the best results.
Picture: How to Simplify Flow Charting — Cross-functional Flowchart
It is easy to recreate any informational system structure using diagrams. There are three main components of any ER diagram: entity, attribute and relationship. Basing on these three components, one can define other, less used elements, such as weak entity or relationship, derived attribute, recursive relationship etc.
This is the set of graphic elements of ERD Chen's notation. This ERD notation is used to represent an entity–relationship models. It involves the set of geometric forms: rectangles - depicting entities, ovals - representing attributes and diamonds depicting relationships assigned for first-class objects, that can have relationships and attributes of their own. Connections are displayed with arrowed lines. It is known that the Chen's ERD notation is used to show a detailed view of entities and relationships. ConceptDraw Entity-Relationship Diagram solution from the Software Development section of Solution Park provides the ability to create ERD of database structure for software development purposes using the Chen’s notation elements.
Picture: Components of ER Diagram
ConceptDraw DIAGRAM diagramming and vector drawing software offers the Business Process Diagram Solution from the Business Processes Area of ConceptDraw Solution Park with powerful tools to help you easy represent the business processes and create the business process diagrams based on BPMN 2.0 standard.
Picture: BPMN 2.0
Audit Process Flowchart, Audit Flowchart - Audit Flowcharts solution for ConceptDraw DIAGRAM Solution Park provides the Audit Flowcharts library with wide variety of predesigned audit flowchart symbols, and also the set of templates and samples allowing you design your own audit flowchart or audit process flowchart in one moment. Simply use any of offered samples and change it for your needs, or fill the desired template.
Picture: Audit Process Flowchart. Audit Flowchart
ConceptDraw DIAGRAM diagramming and vector drawing software extended with Rapid UML Solution from the Software Development Area is a powerful online diagram tool that will help you design any types of UML diagrams simply and fast.
Picture: Online Diagram Tool
The use case diagram (behavior scenarios, precedents) is the initial conceptual representation of the system during its design and development. This diagram consists of actors, use cases and relationships between them. When constructing a diagram, common notation elements can also be used: notes and extension mechanisms.
This sample was created in ConceptDraw DIAGRAM diagramming and vector drawing software using the UML Use Case Diagram library of the Rapid UML Solution from the Software Development area of ConceptDraw Solution Park.
This sample shows the types of user’s interactions with the system and is used at the registration and working with the database system.
Picture: UML Use Case Diagram Example. Registration System
While designing a conceptual data model, you should use appropriate software. For instance, ConceptDraw DIAGRAM is a user-friendly ER diagram tool that has a lot of samples and templates to facilitate your work. A clear entity-relationship diagram helps to define the relations between system’s components.
Software engineering is the section of a computer science engaged to design, realization, and support of complex software products. An ERD is a data modeling method that is widely applied in the software engineering practice. Commonly it is used for developing a structure of a a relational database. An entity relationship diagram is helpful for structuring and organizing databases that can be modeled using a relational structure. An entity relationship diagram is designed to depicts the interrelationships within the sets of entities which are accumulated in the database. Each entity represents a particular component of a data. Thus, ER diagrams depicts the logical structure of databases. ConceptDraw ER Diagrams solution provides software engineers with the professional tool for making entity-relationship diagrams.
Picture: Entity Relationship Diagram Software Engineering
ConceptDraw DIAGRAM diagramming and vector drawing software offers the Timeline Diagrams solution from the Management area which is rich for the timeline examples, samples, templates and ready-to-use vector shapes.
Picture: Timeline Examples
Growth-Share Matrix Software - ConceptDraw DIAGRAM is a powerful diagramming and vector drawing software for creating professional looking Growth–Share Matrices. For simple and quick creating the Growth–Share Matrix ConceptDraw DIAGRAM offers the Matrices Solution from the Marketing Area of ConceptDraw Solution Park.
The Matrices Solution also provides a wide variety of templates and samples that will help you to create the Matrix diagrams of any difficulty.
Picture: Growth-Share Matrix Software