Review Website:

Mark Stevens

Homework 1a

Overview

Spiral Model

Background material:

• Proposed by B. Boehm in May 1988

Major tasks( repeated as necessary) such as:

• customer communication
• planning
• risk analysis
• engineering
• construction and release
• customer evaluation

Strengths:

• The ability to repeat as many times as necessary in the software development

Weaknesses:

• Error may not be detected and it may propagate further down the system.

Appropriate domain:

• Ideal for large-scale systems

Inappropriate domain:

• When customer communication is low.

Prototyping Model

Background Material:

• It is older than the spiral model.

Representation of components and relationship:

Goes through 3 circular steps:

• Customer communication
• Build and/or revise mock-up
• Customer test the software

Appropriate domain:

• Best used on systems that are relatively small scale

Inappropriate domain:

• When customer gives strict guidelines regarding the implementation of the system.

Comparison of the Spiral and Prototyping Model:

• The prototyping model is a simpler version of the spiral model.
• The prototyping model is better suited for early stages of development.
• The prototyping model is inappropriate to be used when the system has already been proven viable but need an upgrade. Unlike, spiral lifecycle which enables rapid replacement and updating, prototyping require rebuilding the software from ground.

Questions anc Comments

1. What are the relationships and rules that need to be considered when using the spiral and prototyping model?
2. What are the related tools and methodologies related to both the models?
3. What are others domain besides the ones listed above?
4. How is the model represented in diagrams? I think it should be clearer if there are diagrams to illustrate the components and relationship.

Homework 2

Overview

Background material and information:

It is a distributed model.

• The client/server architecture emerged in the late 1980s.
• 3 major components:
  • A standalone servers
  • A set of clients
  • A network

Relationship to Lifecycle Models:

Spiral Model

Advantage:

• Has high risk assessment. A client/server is associated with high risk and therefore is must be reliable.

Disadvantage:

• Allows errors to propagate without detection.

Prototyping Model

• Does not work well with the client/server architecture.
• Does not have enough time for thorough time for implementation.

Appropriate uses:

• Most popular use of client/server model is the World Wide Web.
• Client server is also being used throughout industry and the military.

Inappropriate uses:

• It is inappropriate to use the client/server model in small systems that did not involve any type of networking characteristics.

Questions and Comments:

1. Why and in what area that the spiral model ideal for networking systems? Why is this point considered as an advantage to the client/server architecture?
2. I agree that spiral model does have high risk assessment which increase reliability but does a client/server necessary to be associated with high risk? If yes, why?
3. What makes client/server better than other software architecture?

Homework 4

Overview

Data Flow Diagrams (DFDs)

Data Flow Diagrams are diagrams that show the flow of data through a system.

Representation of component:

There are four types of components:

• External entities
• Processes
• Data flow
• Data stores

Relationship and Rules:

• Each process can be broken down into a more simple set of processes.
• All DFDs are traceable.
• DFDs are written from left to right or top to bottom.
• Phrases are used to name data flows and verbs for processes.

Strengths:

• DFDs give a picturistic view of the system.
• The representation is easily understandable.

Weaknesses:

• Complex DFDs can be difficult to understand and may have been detail overlooked.

Appropriate domain:

• Used on a relatively simple system.

Inappropriate domain:

• Complex and real time system.

Tools:

• Example: Microsoft words and Visio

SADT

It is designed to handle more complex method.

Representation of Components:

Can be broken down into two sections

• Requirement specification
• Interpreting the result

Each diagram has four major activities.

• Inputs
• Outputs
• Controls
• Mechanism

The functions are broken into subfunctions.

Strengths:

• Accurate representation for complex systems.
• Avoids clustering by dividing the data.

Weakness:

• Difficult to understand low level process in large system.

Appropriate domain:

• Appropriate to be used in complex systems or an intergrated system.

Inappropriate domain:

• Object oriented activities because it involves the separating of the data.

Tools:

• SADT has a built in automated tools that supports analysis procedures and defines organizational structure.

Questions and Comments

• What other tools that are related to SADT besides the built in tools it?

• In SADT, it has diagrams to represent information. How are they related to each other?

Project 1

Overview

Problem Statement:

This project is about the software which enables the user to keep track of the inventory items in stock and resulted from sales, to update stock records and to project the softwares to purchase.

Current System:

Physical:

The current system consists of manually logging :

1. Customer ID number
2. Title and serial number of the software purchased
3. Date purchased
4. Customer's signature

Into a three-ring binder at the time of purchase.

Logical:

1. Ringing the customer's purchase
2. Completing logbook entry.

Proposed System:

Physical:

The proposed system consists of

1. Scanning purchased item
2. Entering customer information

Logical:

1. Subtracting the purchased item from the current inventory.
2. Adding the purchased into the sales inventory.
3. Verify customer's ID.
4. User update inventory.

Questions and Comments

1. Since the project needs scanning, don't you think that in the hardware required, a scanner should be added as a requirement?
2. How about securities features in the system?
3. Why not include the logbook idea in the current logical system into the proposed logical system? That certainly will make maintenance easier and more organized.

Project 3

Overview

Microsoft Project 98 vs. Open Plan Professional:

This project is about the comparison and contrast of Microsoft project 98 and Open Plan Professional.

The areas that the group compares and contrasts are

• The Look and Feel
• Multiple Views
• Task Splitting
• Project Reminders
• Project Hierarchy
• Hyperlinks
• Multi-user Communication
• Publishing Records

 

Questions and Comments

1. What features make Microsoft Project 98 more outstanding and user friendly that other software management tools?
2. Can you identify which type of projects is more suitable to use Microsoft Project 98 rather than Open Plan professional?