IT216 Systems Analysis and Design

1. Discuss in scholarly detail the importance of destination controls and current methods of implementing them.

2. Discuss in scholarly detail types of control fields that should be printed on reports and why these control fields are important.

3. Discuss in scholarly detail the traditional and Object-Oriented approaches to inputs and outputs.

4. Discuss in scholarly detail benefits of using XML as a system-to-system interface mechanism. In addition, are there any potential disadvantages to this approach and why?

Importance of destination controls Peters (2007) understanding the benefits and limitations of destination dispatch.

Enhances accessibility to the cars. The destination controls assigns a group of people to a specific car depending on their destination. By doing this order in traffic flow is maintained and gives passengers ample time of accessing their assigned cars. The mobile impaired persons are also able to access go to their assigned cars prior to travel thanks to the assignment nature of the destination controls.

Minimal duration of waiting. The destination controls restricts stopping of cars to floors that don’t have traffic. Moreover,   the passengers are allocated to the cars depending on the floor they are headed to. When a car arrives at a floor it picks passengers that have a common destination. This reduces inappropriate stops to floors that maybe one passenger is travelling to. This feature reduces the time of transit from one destination to the other.

Enhanced comfort of passengers. The ability of the destination control to assign passengers transiting to the same destination to a common car eliminates the normal struggles through a crowd of people to press on the button for a specific floor. Once the passengers get into a car the only stop is their destination. A passenger is also able to choose his or her own car of comfort to travel from one floor to the other. The assignment property also eliminates the struggles to enter a certain car for each and every passenger is assigned to a car. Comfort of a passenger is enhanced in that a car is assigned to carry a specified number of passengers thereby giving more space to the passengers. Overcrowding is avoided extremely.

Organization of traffic. With the assignment feature, passengers move from one floor to the other in an organized manner. Overcrowding in the cars and outside the cars and enhances order in the traffic flow.

Method for implementing the destination controls

Zoning division method. This method tends to partition a building into various zones or groupings in order to control the traffic. The number of partitions depends on the number of cars available or present in the building.

Traffic identification method. This tends to provide information on the traffic flow at given sets of interval. It provides the information on the number of passengers going up and those going down and specifies the number of cars in transit either upward or downwards. It also specifies the number of passengers in coming to the car and those outgoing from the car.

Priority evaluation. This method evaluates the most appropriate car that a passenger is most likely to use when he or she makes a hall call. The following parameters are evaluated to find the most suitable car. The waiting time which is how long the passenger has to wait before the car arrives, the loading of the car which states how many passengers the car is carrying at the moment before arriving for the passenger who made the hall call and lastly the distance of the car from the floor where the hall call was made.

Main method. This is responsible for the overall control of all the other methods the zoning division, the traffic identification method and the priority evaluation method as a whole.

Communication channel. Open Communication protocol is used for sending communication signals among the methods of the system. For instance from the main method to the priority evaluation, to the zoning division to the traffic identification.

Types of control fields

Text field control. The function of the text field control is to input, change, format, hold and output text values a character, a symbol or a message.

Hierarchical taxon field control. This field control inputs, changes, formats, updates, holds and output content or fields of a certain hierarchical classification for instance type.

Address field control. Allows inputs, changes, updates, formats and display of contents that are dynamic in nature. For instance the information on a person’s current location according to Google maps.

Flat taxon field control. Similar to Hierarchical taxon field control but the difference is that it holds contents associated with flat taxonomies e.g. tags.

Date field controls. Used to hold contents with date and time value.

Importance of controls fields.

They determine the assignment of control level indicators.E

Ease of changing from one perspective view of the contents to another.

Capability to specify the interaction structured platform.

Traditional Approach to inputs and outputs

It is also referred to as waterfall SDLC because its logic is from one stage to the other. This approach views a system from a top-down perspective. It is a predictive type of approach to a system that leads step by step and is composed of several phases. The phases never run concurrently, activities in one phase must be processed and complete for it to go to the following phase or step. This approach demands a well specified requirement specification prior to the development of the system.

Advantages of traditional approach to inputs and outputs.

It is user-friendly. It is easy and simple to understand and use.

It has clearly stipulated logical steps that flow from one activity to the other.

Appropriate for smaller systems whose requirements are well spelt out or specified.

Disadvantages of traditional approach to inputs and outputs

Testing is done in the late stages of the development process therefore error correction is very difficult because errors that occurred in the first stage may propagate to the last stage. This makes it difficult to trace the source of the error.

It is not adaptive. It does not encourage or support incorporation of other new needs or ideas. Its scope is rigid Hoffer (2006)

Risk prevalence and uncertainty is very high with this approach because if one vital function is left out it cannot be incorporated back to the system. Making it more disadvantageous approach to inputs and outputs.

Object oriented approach to inputs and outputs

Object oriented approach views a system from the bottom-up perspective. It encompasses data, information and processes into objects. Unified Modeling Language UML is used to express various performances and views of the system through diagrammatic and model representations. When objects oriented approach is combined with other methods of system development it is termed as unified process which is iterative and incremental. This is done to enhance the productivity of the System analysis and design. This is where objects are grouped into classes and structures in order to share certain resources, functionality and behavior. Inheritance, encapsulation and polymorphism are also feature of object oriented approach used. OOA has no recognized standards of operation.   

Benefits of using XML as a system to system interface mechanism Nurmilaakso (2008).

Interpretability and usability. XML has a capability of being interpreted by a variety of platforms and programming tools that enhances its usability as a system to system interface. It also contains a vast range of tools for representing, expressing and exchanging data within projects.

Compatibility. As per the name Extensible Markup Language XML is a subject of incorporation of new standards and technologies according to Kokkonen (2003). The developers of XML named it that way keeping in mind the room for extension of the capabilities and standards of XML. In addition, the XML gives programmers the mandate to create their own Document Type Definition which includes extensible tags.

User-friendliness. XML is easy to comprehend and use because it uses reserved English words both by the programmer and the computer. XML files are created on the basis of structures whose complexity may grow according to the set of layers the structure has. But these structures are easy to figure out and put into use.

Schemas.  XML schemas give XML the ability to hold information on data and give an extended and compatible data appearance.

Unfortunately the use of XML as a system to system interface mechanism has some drawback. Disadvantages of XML as a system to system interface mechanism.

It promotes the use of unrelated structures of data.  There is no normalization of data in terms of the first, second, third, fourth normal.

Parsing XML files is more difficult compared to parsing flat files. The duration of time taken to retrieve data and information is long and also requires many lines of code for it to be accomplished.

References

Hoffer.j, George.j,&Valacich.j 2006.Mordern Systems Analysis and design 6^th. Prentice Hall: U.S.A

Kokkonen, T., Jolma, A., and Koivusalo, H. (2003), Interfacing environmental simulation

models and databases using XML, Environmental Modelling and Software, 18(5), 436-471.

Nurmilaakso, J.M.(2008). Adoption of e-business functions and migration from EDI-based to XML-based e-business frameworks in supply chain integration. International Journal of Production Economics, 113(2), 721-723.

Peters .R,(2007).Understanding the benefits and limitations of destination dispatch. Elevator world, 55(11), p.88.