Systems Engineering, Term Paper Example

Steps used in constructing and modeling the ERD with specific emphasis surrounding outputs from the Lesson Exercises

An entity-relationship diagram (ERD) encompasses software engineering abstract descriptions representing a distinct database model (Modell, 2003).

Sample entity relationship diagram (ERD) (Modell, 2003).

For example, an ER model would define an element as an entity such as phone number being entities. Subsequently, the relationship between a person and the ascribed phone numbers could be described as ‘has a phone number’ (Modell, 2003, p. 10). Diagrams are designed to interpret these relationship entities. They are called entity relationship diagrams (ERD). Steps utilized in creating them are unique and are classified according to various schema approaches. Currently there are three levels of entity relationship strategies utilized in constructing these models (Beynon-Davies, 2004).

Conceptual data model is the highest level representing an overview description of the system showing the extent of relationships occurring among entities. This is a foundation establishment for other models within the entity relationship (ER) framework. Logical data modelling is the next step entity relationship (ER) descriptions. However, while the conceptual model forms a foundation for all other descriptions, the basic representations could be omitted in this stage/step if relations only require creating distinct information systems (Beynon-Davies, 2004).

Physical data model is the third schema application being constructed from each logical entity represented in the design. Here is where details for creating a database are stored. Essentially, the first stages of information system design embrace the use of these entire three schemas, when requirements analysis is being pursued. This approach is used to describe the type of information the database store being applications of a data modelling technique. Some information technology analysts may use the terminology physical data model in interpreting functions applicable to the entire entity-relationship network (Beynon-Davies, 2004).

An entity-relationship diagram (ERD) is a unique device applied to database construction when information systems are utilized within an organization. Further descriptions offer the proposition that entity-relationship diagrams (ERD) are independent structures rather than interdependent ones. Precisely, entities emerge from abstract concepts embodied in oceans of complexities referred to as domains. The aims is to distinguish real world experiences/occurrences/features one from the other by categorizing each as a separate entity within specific domains (Stevens, Brook, Jackson, & Arnold, 1998).

Computer- aided software engineering (CASE) also classified as DeSign CASE is a method of developing information systems within the software process design mechanism. The technological development emerged from the Michigan University Information System Design and Optimization System (ISDOS) project, which began in 1968. There are four major components of this device. They are the diagramtic tool; information repository; interface generators and management tools (Stevens et.al, 1998).

CASE functions by utilizing three categories of supporting software. They are tools, workbenches and environments. CASE tools automate several activities along the life cycle phases when establishing functional requirements status. Prototyping tools are applied when creating graphic models. Further, tools currently utilized in CASE designs are life-cycle support; integration dimension; construction dimension and Knowledge-based CASE dimension (Stevens et.al, 1998).

Life cycle based CASE tools occur as upper and lower CASE tools describing activities they support in the information life cycle. Upper CASE ignores the design mechanisms with the database structure, but focuses on supporting strategic planning and traditional diagrammatic language while building concept products. The lower CASE segment aims at monitoring backend activities such as component integration; debugging; physical designs and maintenance processes. Workbench achieves consistent homogenous interface and facilitates tools innovation (Stevens et.al, 1998).

An environment is a collaboration of CASE tools and workbenches supporting software processes. The focus base integration encompasses language-centered designs; process centered programs and fourth generation development. Implementing these programs are very useful to information system development because every aspect of the software creation could be supported by appropriate tools (Stevens et.al, 1998).

Organizations that implement CASE, however, must be aware of unrealistic expectations and guard against its influence in accepting the efficiency of the database that is produced from the intervention. The implementation may be slow and are not recommended if information systems are being implemented for the first time. There may be weak repository controls producing breaches in the system (Stevens et.al, 1998).

References

Beynon-Davies, P. (2004). Database Systems. Houndmills, Basingstoke, UK: Palgrave

Modell, M. (2003). Chapter-10: Modeling and Diagramming Techniques. A Professional’s Guide to Systems Analysis (2nd ed.). New York, NY: McGraw Hill.

Stevens, R. Brook, P. Jackson, K., & Arnold, S. (1998). Systems Engineering: Coping with Complexity. Prentice Hall.