Assignment on Designing a Computer System Application

Introduction:

            System development life cycle is a process of altering or creating information systems and the methodologies and models that people use to expand these systems. It is a process to develop the information system which includes requirements, training, and validation and user ownership. There are some approaches in SDLC like spiral, waterfall, agile software development, and incremental, rapid prototyping and synchronize and stabilize. Business process modelling is the representing process of an organization which is used to improve and analyze current process.
It is performed by the business analysts and managers who are responsible to improve the process quality and efficiency.  Unified Modelling Language (UML) is a modelling language of an object oriented software engineering which is used to modify, specify, visualize, document and construct the artifacts of an object oriented software-intensive system under development. It includes activities, actors, business process, database schemas, logical components, programming language statements and reusable software components. SDLC, BPM and UML are very important for an organization for its smooth operation. In this assignment I will discuss the SDLC, BPM and UML of an organization named The Floor Ltd.  

Part -1

102.1.1 Distinguish between the features and approaches adopted in the SDLCs in used in systems development.

A system development project has four fundamental phases like planning, analysis, design and implementation. There are two kinds of approaches like traditional and object oriented. The most common traditional approach is waterfall model where it follows a formal step-by-step approach to the SDLC phases and activities. Here one phase must complete before moving to the next step. In this approach after completing of each phase or activity, a document is reported to the stakeholder for approval to move in the next step.

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The main phase of the structured approach is the process model which describes the business processes of a system and the tool used to present this model is the data-flow diagram or DFD. DFD contains info regarding the systems components that need to be designed and ultimately built.

            Another approach of SDLC is object-oriented (OO) methodology where it is originated from the software engineering professionals who deal with the system development in business, process control and aerospace. The failure of this process sometimes cost life. The OO approach follows an incremental and interactive approach to system development. The SDLC is viewed as consisting of several phases or increments like inception, construction, elaboration and transition. In each phase the developers gather requirements, analyze the requirements, designing the system, implementing the design and testing the system.

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102.1.2 Utilise two different SDLC approaches to develop one small real world project.

            I will discuss the waterfall model and RAD model. The waterfall model will describe in the following part:

The waterfall model is falling down on its way. The main principle of this model is what affects people’s perception of what it does and hence how it is implemented. There are four phase in waterfall model: decide, design, develop and demonstrate phase. In decide phase it describe business case, user requirement and system specification. In this case the business was selling carpets and other makes laminated wood products. They supply the finished goods to the wholesalers and direct users. Now they want to expand their business through the Europe and for that reason they want to develop an IP based information system which is capable of doing sales, handle product with security, response to customer queries and produce report to management and stuff. In design section it will cover system and component design. In develop phase it will cover construct component and in demonstrate phase it will describe the testing system.

                                                   

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The RAD model:

            The RAD (rapid application development) is a idea where a product can be developed quickly and of higher quality through:

·         Gathering requirements using workshops or focus groups

·         Early and prototyping, reiterative user testing of designs

·         The re-use of software components

·         A very fixed quick schedule that defers design improvement to the next product version

·         Less reviews system and other team communication.

It has the 5 phases: business modelling, data modelling, process modelling, application generation and testing and turnover. In business modelling phase it will describe the company information for driving the business process, what information need to be generated, the information will share to the buyer and sellers and everybody can access the information and so on. In data modelling phase info is collected from business modelling and refined into a set of data objects which is needed to support the business. Process modelling will process the data for adding, deleting, modifying or retrieving a data object. [4]

102.1.3 Compare the approaches taken in the development of a single project showing the benefits and disadvantages of each.

            The advantage of waterfall model is that it allows for managerial control and departmentalization. Each stage of development has a schedule time frame and a product can proceed through the development process and theoretically be delivered on time. Development involves concept, design, implementation, testing, installation, troubleshooting and ends up at operation and maintenance. Every phase is in strict order without any overlapping or iterative steps.

            The disadvantage of waterfall model is that it doesn’t allow for much revision or reflection. If one stage is completed it is really difficult to go back to the previous stage to change something. This drawback can be overcome by joint application development or rapid application development or synch and stabilize, build and fix and the spiral model.  

RAD deducts the development time and reusability of components help to gear up the development. It is easy to work as it is modularized. For this project it needs very highly skilled engineers in the team. Both the end consumers and moderators should be agreed to complete the system in a much shorter time frame otherwise the RAD will fail. It is an object oriented approach and it is difficult to modularize the project the RAD may not work well. [4]

102.2.1 Differentiate between the different project management approaches in current usage.

            Project management is the process of planning, arranging, securing and managing resources to gain a certain goals. There are some approaches like the traditional, CPM, extreme project management, event chain methodology, agile project management and so on. I will describe some of those approaches.

The traditional approach: the traditional approach has four stages plus control and they are initiation, planning and design, execution and construction, monitoring and controlling system and completion.

                                                

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All the projects will not have all of these stages; sometimes some projects repeat each step for several times. Like working on a brick and motor design and construction, project will have pre-planning, conceptual design, design development, construction drawing and construction administration stages. Waterfall model are followed for software development.

            Chain project management (CPM) is a process of planning and managing projects that puts more emphasis on the resources needed in order to execute project tasks. The project plan should have resource levelling and the longest sequence of resources-constrained task should be considered as the critical chain. In multi-project condition, resource levelling should be performed across the project. It has a drum resource which is constraint across the project.

                                                          

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            PERT is a method to analyze the related tasks in completing a given project, specifically the time needed to complete each task and identifying the minimum time required to finish the total project. It is developed to simplify the scheduling and planning of complex and large project. This is being used in US navy in 1957. It is an event-oriented technique rather than start-and completion-oriented. It is being used in very large-scale, complex, one-time, research, non-routine infrastructure and development project.

                                       

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102.2.2 Undertake a small real world project using a recognised project management approach.

            I am choosing event chain methodology for this project because it is a large project and it depends on the economic condition of the country. It is an uncertainty modelling which focus on identifying and managing events and event chains that affect the project scheduling. It helps to mitigate the negative impact of biases and psychological heuristics. This project is completely suitable for ‘The floor ltd’ project because

·         The activity is related to real-life processes and it is affected by external events

·         This is an event chain project which creates another event. Like if there an alternative product of carpet is created then we need to change this event and need to rearrange the project

·         The buying capacity of buyers is the main and most effective factor in this project.

·         If the project is partially completed and data about the project cost, duration and events occurred is available, it is still possible to refine info about future potential events and helps to predict the future project performance.   

102.2.3 Justify the choice of project management approach taken

            For justifying the choice of project management approach we need to use COCOMO. COCOMO is being used for calculating project time, how many people required and how much effort we need to give. Here for this project I choose event chain methodology which is quite suitable. After calculating the effort, time and people we will see it the best suited model for this project. Our project is a semi-detached project where medium team is required with mix of rigid and less than rigid requirements.

Effort Applied (E) = a_b(SLOC)^b_b [ man-months ]

Development Time (D) = c_b(Effort Applied)^d_b [months]

People required (P) = Effort Applied / Development Time [count]

where, SLOC is the estimated number of delivered lines (expressed in thousands ) of code for project, The coefficients a_b, b_b, c_b and d_b are given in the following table.

Software project	ab	bb	cb	db
Organic	2.4	1.05	2.5	0.38
Semi-detached	3.0	1.12	2.5	0.35
Embedded	3.6	1.20	2.5	0.32

It’s a semi-detached project and after calculating it needs around 50 people and time needs around one month to complete this IP based information system. [6]

Gantt chart of this project:

                     

Part - 2

102.3.1 Analyse the different stages of business process modelling (BPM)

            There are different types of business process modelling but there are some common features. I will describe the different stages of the BPM in the following part:

·         The organizational model illustrates the roles and areas of responsibilities within the organization according to the activities of a business process. It represents a more static view of a process

·         The control flow illustrates the order of execution and the dependencies between the various activities

·         The data flow explains how the business entities are manoeuvred by different activities.

·         Use cases explains the context of a business process and it’s a visible characteristics

·         Collaboration diagram can further document how business agents and artifacts work together to perform a function.  

                                          

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A workflow is a description of a series of actions, affirmed as work of a person, work of a complex or simple mechanism, work of an organization of staff, work of a group of persons, or machines. It may be seen as any concept of segregated in work share, real work, work split or whatever types of ordering. For control purposes, workflow may be a view on real work under a chosen aspect. The artifact-centric process modelling approach fosters the automation of the business operations and supports the flexibility of the workflow enactment and evolution.

102.3.2 Discuss the benefits and disadvantages of the BPM approach

Benefits of the BPM approaches:

·         Formalize existing process and spot needed improvements

It formalizes the current processes for smooth running. It helps to do the potential improvement like the removal of steps, the reengineering of a part, automation of manual steps or the whole of the flow. 

·         Facilitate automated, efficient process flow

BPM software drives the process flow, downtime between works is almost null, unless the software workout. It support process parallelism so that different serial of work can be performed simultaneously in isolation of each other, with merging result and synchronise later in the flow. The process can control by emails, phone calls or inter-office.

·         Increase productivity and decrease head count

It intensifies the work done with less people. It reduced the man power while reducing time and increasing customer satisfaction.

The disadvantage of the BPM is that it reduces the number of employees for that reason many organizations reduce their employees and many semi-skilled employees lost their jobs. 

102.3.3 Undertake a small real world project using BPM techniques

 

I am using event-driven process chain for this project:

                                    

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Event 

            Here the event is we need to create an IP based information system where salesman can sale, handle payment, responding customer inquiry and producing a report to management and stuffs. An EPC diagram must start with an event and end with an event.

Function 

            It is the active element of this BPM. They model the activities or tasks within the company. It is the transformation from beginning to end state. Functions can be refined into another EPC which is called hierarchical function. Here we are using hierarchical function.

Organization unit 

            Here the office stuffs or management are responsible for those specific functions.

Information, material, or resource object 

In the EPC, the information, material, or resource objects portray objects in the real world.

Logical connector 

In the EPC the logical relationships between elements in the control flow, that is, events and functions are described by logical connectors.

Control flow 

It connects events with functions, process paths, or logical connectors creating chronological sequence and logical interdependencies between them.

Information flow 

Information flows show the connection between functions and input or output data, upon which the function reads changes or writes.

Organization unit assignment 

Organization unit assignments show the connection between an organization unit and the function it is responsible for.

Process path 

Process paths serve as navigation aid in the EPC. They show the connection from or to other processes. [8]

102.4.1 Analyse the role of UML in the chosen SDLCs

                              

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For waterfall approach GMF framework is being used. The traditional UML methodology is being used in waterfall approach. It allows modelling at a high level of abstraction with no code generation at this early stage, to use internal tool model then to map GEF to EMF inside the GMF framework and finally produce a standard XMI from the internal and graphical models.             

        

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This UML is being used for object oriented approach.

EclipseUML 2008 is more than just a "waterfall" UML tool because it is specially designed to:

• Deduct the cost of fixing bugs which make it too far downstream in the waterfall process
• incrementally get better an organization’s performance and bring solid business value
• decrease improvement costs
• help an organization to adapt effectively and quickly
• allow more predictable delivery schedules

102.4.2 Analyse the role of UML in business process modelling

            The unified modelling language (UML) is used to visualize, specify, construct, modify and document the artifacts of object-oriented software under development. It is an architectural blueprint of business process modelling (work flow). The popularity of UML has caused to be promoted as a notation for business modelling as well as its actual motive of modelling object oriented system.

            UML diagram, which is frequently proposed for business process modelling, are the use case and activity diagram. A use case diagram shows processes in a non-sequential representation, while activity diagrams shows sequence in a manner like to a flowchart. The UML allows the activity diagram to be used to pasteurised procedural flow of control in several contexts, from classes and operation implementation to use cases.  [10] 

                                                                              

102.4.3 Discuss how the different features of UML map to the stages of the chosen SDLCs

            UML is an object oriented design and we use RAD design for SDLC which is also object oriented methodology. Both aspects are closely related to each other. UML is a use case drive which is the primary modelling tools to define the system behaviour. In here it will describe how the user interacts with the system to perform activity. The UML is architecture centric which gives a high level of view of the system being improved. The system architecture must support three views of system like functional view, static view and dynamic views. SDLC is a gradual process for system development and UML diagrams used in OO- based development and improvement moves from a conceptual and abstract thing in the analysis and design phase to become more and more detail in the implementation phase. 

102.4.4 Undertake a small real world project using UML

Here I will describe only the order portion like one customer want to give an order or he already gave an order and how he will be served by ‘The Floor ltd’. Those are the cases:

1.       an ordered is placed by a single customer

2.       a customer can place a number of order

3.       an order may edited or deleted before being serviced

4.       a giver items cannot be selected more than once in a same order

5.       one order must contain one item

6.       the required quantity of a placed item must be available

7.       an order is serviced when the customer pay the full amount of money

8.       the order can only served when the items are only available in stock

9.       the customer can pay cash or check

10.   the credit card must be the name of the owner

11.   the validity of credit card must not exceed within two weeks after placing the order

12.   the credit limit must be exceed the due bills

                          

                                                    Customer registration subsystem

                            

                                                          Inventory management system

      

                                                The purchasing subsystem

Conclusion:

            We live in modern world where we have to compete in every step in everyday life. Huge competition is prevailing among the business owners to achieve the market places. The Floor ltd is a store of carpet and other household flooring materials. They want to change their business policy, now they want to move their business to IP based information system where people can place their order in internet, pay their bills and so on. For that reason they need a strong IP based information system to improve their present condition. For changing their current strategy then need system development life cycle. They can follow traditional or RAD model but RAD model is more effective than waterfall model. For completing this project they can follow different project management system. After that they do the business process modelling then the developer use UML for depicting the business process model. When they will create the system, management and official task will be easy and time effective.        

References:

1.       Image of waterfall model, Retrieve on : 30/08/11, Available on : http://users.evtek.fi/~jaanah/DPAD/lectures/lec2/water_m.html

2.       LiveNotes from Dinoop’s COIS20025 Blog, Retrieve on : 30/08/11, Available on : http://www.google.co.uk/imgres?q=object+oriented+sdlc+approach&hl=en&sa=X&biw=1366&bih=667&tbm=isch&prmd=ivns&tbnid=HiLNQ_4uyqfm6M:&imgrefurl=http://dinoop.wordpress.com/&docid=cbZvjxuhBcsBUM&w=448&h=222&ei=HNJfTo_tKKKHmQWqg7wU&zoom=1&iact=hc&vpx=604&vpy=124&dur=7398&hovh=158&hovw=319&tx=110&ty=115&page=1&tbnh=105&tbnw=212&start=0&ndsp=15&ved=1t:429,r:2,s:0

3.       Waterfall model, Retrieve on : 30/08/11, Available on : http://www.coleyconsulting.co.uk/waterfall-model.htm

4.       SDLC model, Retrieve on : 30/08/11, Available on : http://www.onestoptesting.com/sdlc-models/

5.       Project management , From Wikipedia, Retrieve on : 30/08/11, Last modified: 30/08/11, Available on : http://en.wikipedia.org/wiki/Project_management

6.       COCOMO, From Wikipedia, Retrieve on : 30/08/11, Last modified: 30/08/11, Available on : http://en.wikipedia.org/wiki/COCOMO

7.       Business process modelling, From Wikipedia, Retrieve on : 30/08/11, Last modified: 30/08/11, Available on :http://en.wikipedia.org/wiki/Business_process_modelling

8.       Event-driven process chain, From Wikipedia, Retrieve on : 30/08/11, Last modified: 30/08/11, Available on :http://en.wikipedia.org/wiki/Event-driven_process_chain

9.       Waterfall versus incremental modelling cycle, Retrieve on : 30/08/11, Available on : http://www.forum-omondo.com/documentation_eclipseuml_2008/waterfall_versus_incrementale_modeling_cycle.html

http://www.bptrends.com/publicationfiles/popkin%20-%20whitep%20integ%20bp%20models%20and%20uml%202-04-03.pdf