Software engineering

1/100 童友社零戰

2009-02-22T06:24:00.000-08:00

【簡單模型節】完成品 3

2008-11-27T06:46:00.000-08:00

【簡單模型節】完成品 2

2008-11-27T06:45:00.000-08:00

【簡單模型節】完成品 1

2008-11-27T06:38:00.000-08:00

香港人的【簡單模型節】小進度

2008-11-09T00:32:00.000-08:00

香港人的【簡單模型節】

2008-10-22T06:36:00.000-07:00

開工了, 按閻大的意思作三件吧.
Bf 109, Ar 234及XXX

Why do software projects fail so often?

2006-03-17T00:56:00.000-08:00

Why do software projects fail?

1. Lack of User Inputs
2. Incomplete Requirements & Specifications
3. Changing Requirements & Specifications
4. Lack of Executive Support
5. Technology Incompetence
6. Lack of Resources
7. Unrealistic Expectations
8. Unclear Objectives
9. Unrealistic Time Frames
10. New Technology
11. Other

source: http://www.stylusinc.com/Common/Concerns/SoftwareProjectsFailure.php

What can we do to make them succeed?

A formula for project success:
success = planning * execution

There are ten keys to make successful software projects:
1. Clear vision
2. Stable, complete, written requirements
3. Detailed user interface prototypes
4. Effective project management
5. Accurate estimates
6. Two-phase budgeting
7. A focus on quality
8. Technology expertise
9. Active risk management
10. Remember, software is created by humans

source: http://www.issre2001.org/10KeysToSuccess.pdf#search='software%20project'

What is the importance of software project management?

Software Project Management is a sub-discipline of Project management in which software projects are planned, monitored and controlled.
The purpose of Project Planning is to identify the scope of the project, estimate the work involved, and create a project schedule. Project planning begins with requirements that define the software to be developed. The project plan is then developed to describe the tasks that will lead to completion.
The purpose of Project Monitoring and Control is to keep the team and management up to date on the project's progress. If the project deviates from the plan, then the project manager can take action to correct the problem. Project monitoring and control involves status meetings to gather status from the team. When changes need to be made, Change control is used to keep the products up to date.

source: http://en.wikipedia.org/wiki/Software_project_management

What is test-driven development?

2006-03-04T05:19:00.000-08:00

What is the main idea of test-driven development?

Test-driven development (TDD), is an evolutionary approach to development which combines test-first development where you write a test before you write just enough production code to fulfill that test and refactoring.

What is the goal of test-driven development?

One view is the goal of TDD is specification and not validation. In other words, it' s one way to think through your design before your write your functional code. Another view is that TDD is a programming technique. So, the goal of TDD is to write clean code that works.

How does a test-driven development cycle look like?

Please refer to the diagram above.

source: http://www.agiledata.org/essays/tdd.html

Software Design Patterns: How much do you understand?

2006-02-19T00:50:00.000-08:00

In the three design patterns, the most I understand are structural patterns (especially the adapter and bridge design pattern).

The adapter pattern uses both inheritance and delegation.
For example, when two systems A nad B are totally different and cannot be modified, an adapter is needed. The adapter implements each method declared in A in terms of requests to B.

According to the textbook, the bridge pattern decouples the interface of a class from its implementation. It serves the same purpose as the adapter pattern except that the developer is not constrained by an existing component.
Maybe we use the example above again. This time, a subsystem C is added to B. However, there maybe some changes to C and B doesn't know, a bridge pattern is needed.
It acts as in interface to C and B, implements method to C and B.

Sorry to Steven that I'm not clear of the behavioral and creational patterns.

Software quality: What makes a program code good?

2006-01-27T06:16:00.000-08:00

1. Comments should be dropped in the program codes.

2. Less resources required will be perfered first.

3. Stable and reliable.

4. Meaningful instances would be better, such as "int salary" instead of "int s".

5. Useless codes should be deleted to lose weight the program.

Stuff that lets agile software developers show off what they believe in

2005-12-19T07:09:00.000-08:00

"Born To Refactor":
In software engineering, the term refactoring means modifying source code without changing its external behavior, and is sometimes informally referred to as "cleaning it up". In extreme programming and other agile methodologies refactoring is an integral part of the software development cycle: developers alternate between adding new tests and functionality and refactoring the code to improve its internal consistency and clarity. Automated unit Testing ensures that refactoring does not make the code stop working.
Refactoring does not fix bugs or add new functionality. Rather it is designed to improve the understandability of the code or change its structure and design, and remove dead code, to make it easier for human maintenance in the future. In particular, adding new behavior to a program might be difficult with the program's given structure, so a developer might refactor it first to make it easy, and then add the new behavior.
An example of a trivial refactoring is to change a variable name into something more meaningful, such as from a single letter 'i' to 'interestRate'. A more complex refactoring is to turn the code within an if block into a subroutine. An even more complex refactoring is to replace an if conditional with polymorphism. While "cleaning up" code has happened for decades, the key insight in refactoring is to intentionally "clean up" code separately from adding new functionality, using a known catalogue of common useful refactoring methods, and then separately testing the code (knowing that any behavioral changes indicate a bug). The new aspect is explicitly wanting to improve an existing design without altering its intent or behavior.
The term is by analogy with the factorization of numbers and polynomials. For example, x2 − 1 can be factored as (x + 1)(x – 1), revealing an internal structure that was previously not visible (such as the two roots at +1 and –1). Similarly, in software refactoring, the change in visible structure can often reveal the "hidden" internal structure of the original code.
Refactoring is done as a separate step, to simplify testing. At the end of the refactoring, any change in behavior is clearly a bug and can be fixed separately from the problem of debugging the new behavior.
Martin Fowler's book Refactoring is the classic reference. Although refactoring code has been done informally for years, William F. Opdyke's 1993 PhD dissertation [1] is the first known paper to specifically examine refactoring. All of these resources provide a catalog of common methods for refactoring; a refactoring method has a description of how to apply the method and indicators for when you should (or should not) apply the method.
Refactoring is such an important concept that it has been identified as one of the most important software innovations by author and commentator David A. Wheeler.

source: http://en.wikipedia.org/wiki/Refactor

"JsUnit":
JsUnit is a Unit Testing framework for client-side (in-browser) JavaScript. It is essentially a port of JUnit to JavaScript. Also included is a platform for automating the execution of tests on multiple browsers and mutiple machines running different OSs. Its development began in January 2001.

source: http://www.edwardh.com/jsunit/

Software Engineering Certification Programs:What Can You Learn from Them?

2005-11-26T02:18:00.000-08:00

Compare the CSDP body of knowledge with our current Software Engineering course,
the things that are not in our textbook:

1. Engineering Economics
2. Professional Practices
3. Specialized Software Design Approaches
4. Code Design, Organization, Documentation, Tuning, Defect Identification and Correction.

Since I'm still going with my current Software Engineering course, so I can just find out the differents between the CSDP and MT356F that I've learnt.

UML Tools: What is your favorite?

2005-10-16T08:06:00.000-07:00

In the lesson, I had tried Poseidon for UML Community Edition.
It was quite user friendly (I was thinking am I using the Microsoft Office at that time? haha),
but I had a problem that it was not easy to make a correct association or link in the classes or objects.........it was too hard for me, baby........

On the other hand, I found out that we can draw UML diagrams by Microsoft Visio 2003.

What do you think about the basic skills for software engineers?

2005-10-01T02:16:00.000-07:00

As I read the chapter 1.2 from the textbook, it mentions that

"software engineers deal with complexity through modeling, by focusing at any one time on only the relevant details and ignoring everything else.
In the course of development, software engineers build many different models of the system and of the application domain."

So firstly, I think software engineers must well-known in modeling.

Secondly, since there is no infinite resources, so software engineers must know what condition they are under (e.g. deadline) and spend the budget in the best way.

Thirdly, I think software engineers should be self-possession and have clear minds, these two things can help them in problem solving.

I love my bass

2005-09-22T02:45:00.000-07:00

I love my bass.