Functional and Structural Modeling Coursework Example | Topics and Well Written Essays - 750 words

Functional and Structural Modeling - Coursework Example Introduction Functional modeling generally deals with the activity of developing models of devices, objects and processes of a system based on their functionalities. It is basically concerned with representing knowledge about functions which forms a basis for solving problems related to system representation. It shows how general system goals are achieved through the realization of the sub goals via the system sub functions. According to Tauber, functional model represents a part of the designer’s intention, the design rationale. (pg 12). Structural modeling on the other hand entails data structure description, that is, it describes the structure of data that is supports the business processes of an organization. There are different ways of representing the structure of data used in a system including class diagrams, object diagrams and CRD cards. Structural modeling Structural modeling in system analysis and design is useful in various ways but the main purpose of structural models is to represent ideas, things and important concepts in the application domain. In addition, structural models are used to create a vocabulary for analysts and users. According to Wixom, It is also used in order to reduce the schematic gap between the real world and the software world ( chpt 7 pg 6) Classes, attributes, relationships and operations constitutes the four major components of structural modeling. Classes are templates for creating objects or instances and can either be concrete or abstract. Classes’ example may include user interface data structure and application domain. Class diagrams are used in structural modeling to represent classes, show their attributes, operations and their relationships. Attributes on the other hand are used to describe classes and only important and relevant attributes to the task are included in the structural modeling. An attribute can be public, private or protected depending on its visibility type. Objects or instances can t ake actions known as operations while relationships show how classes are associated. Operations can be broadly grouped into update (changes value of attributes), query (makes information about state available) and constructor which create an object. Functional modeling Functional modeling include various design element such modules, processes inputs and outputs, interfaces and design of databases and files. A fully functional system is made up of a collection of small independent subsystems called modules. The modules are coded and designed separately after which they are brought together to form a complete and fully functional system. Shared use and size are some of the factors to be considered while coding a designing a module. Limiting the number of instructions in a module ensures a small size module which recommended compared to a large module. Duplication of functions in modules should be avoided by creating a single module which can be called by other modules in case of need. System functions consist of processes which are specific acts with definable beginning and ending points beside inputs and outputs. Processes may be distinct but share certain common properties such as: processes identify what is done and not how, they posses definable starting and ending points, processes are carried out irrespective of organizational structure. Interface is an important part of any computerized system since it provides the platform for the user to interact

Asbestos Essay Example | Topics and Well Written Essays - 2250 words

Asbestos - Essay Example An estimated 1.3 million employees in the construction and general industry are at risk. No doubt, we are exposed to a certain level of asbestos material all the time. Asbestos, in the finished form, does not pose any health hazard. Remodelling, repair, maintenance, demolition, sale and transport combined with rough handling all can release these deadly fibres into water or air2. Inhalation of these fibres for a continuous period could be extremely dangerous. . Chrysotile, a fibrous mineral which neither burns nor rots, flexible with maximum tensile strength, extremely useful, lightweight, can create a formidable surface mixed with cementing materials, could be used as high temperature seals and gaskets, known over 2000 years, first mined in Russia, Italy and Canada. Old products, unlike today's improved technological ones, crumbled easily under pressure and released more harmful fibres. All these fibres are non-inflammable Asbestos is a highly emotive topic with two shrill schools of thought, one saying that asbestos should be banned; another arguing that asbestos of today would not be a killer. European Union (EU)3 and the United Kingdom (UK)4 both argue that asbestos is carcinogenic and targets multiple organs of the dust inhaler. According to their rules all types of asbestos are harmful and there is no safe level of exposure and the weight of evidence to support this is incontrovertible and historical. It is impossible to control the exposure to asbestos in workplace and hence, alternative products must be used. Asbestos should be discarded as a harmful object and should be banned, to protect public health. This risk-based approach depends on the fact that there is no identified lower exposure limit to which workers can be safely exposed.5 In spite of the overwhelming medical reports, there is little scientific research evidence to back this viewpoint and the entire exercise seems to be more of a public emotional grandstand. Asbestos is heat resistant and is used in a wide variety of industrial and domestic appliances and this makes it particularly difficult to avoid it completely. It is a mineral fibre used in a variety of building construction materials for insulation and it is also a fire-retardant. The necessity of completely stopping the usage too is questioned by many scientists. The Canadian Chrysotile Institute