Hannes's Mind Maze

Developing on USB memory sticks

2008-06-04T10:36:00Z

Jeff Atwood from Coding Horror fame recently wrote about USB memory sticks and why we don’t ‘yet’ put our whole computing environment one a flash drive. Basically it comes down to speed according to him. Personally, for the last year or so with no problems, I’ve been using my memory stick to store development code on so that I can easily work between different machines. At work I check the code out onto the stick, take it out and work disconnect at home on another machine. Next morning I just plug in my stick and commit the changes to the repository. Obviously the environment needs tweaking, for instance when dealing with databases etc. Also check the company policy regarding security.

System Analyst Questionare

2008-05-16T10:53:00Z

Hi all. I’m planning to start a System Analyst user group at my work but first I need to do some homework.
So I want to ask the following questions to you.

1. Have you ever work with an SA and know what a SA does?
2. Do you think SA’s are needed and have a role to play?
3. If you think so, please tell me what role you see the SA perform?
4. What typically do you think a SA should be able to deliver?
5. Do you see yourself becoming a SA? Reason?

Thanks for your input.

Jimmy Nilsson is coming to Cape Town

2008-01-15T10:46:00Z

In collaboration with PBT Group in Cape Town, South Africa, Jimmy Nilsson will be giving a presentation called "Is Domain-Driven Design more than Entities and Repositories?" and Niclas Nilsson will give a presentation called "Dynamic Languages for Statically Typed Minds". Read more here.

VS2008 IntelliSense for Visual Basic

2008-01-10T14:43:00Z

Lisa Feigebaum from the VB team recently wrote two posts about VS2008 IntelliSense for Visual Basic. Read it here and here. The VS2008 IDE tools for VB.Net surely makes it the most productive tool for building .Net application today.

Code Examples

2007-11-30T12:29:00Z

<rant>One of the most irritating things for me when looking at partial code examples is that they never tell you which components to reference or which namespaces to use / import. </rant> :-(

Going from VS2008 Beta to Release

2007-11-28T06:29:00Z

If you, like me, have to upgrade from VS2008 Beta to VS2008 Release a good place to start is to read Scott Guthrie post on Steps to Uninstall VS 2008 Beta2 before installing the VS 2008 Final Release.

.Net 3.0 and .Net 3.5 Books

2007-11-26T14:09:00Z

Two books that I recently added to my little library that I think everyone moving to .Net 3 and .Net 3.5 will find very useful are

Pro C# with .NET 3.0 Special Edition
	Andrew W Troelsen Hardcover, 1186 pages 238 x 179 x 52mm (L x W x H) ISBN-13: 978-1-59059-823-8 2007 Published by APress

and

Pro ASP.NET 3.5 in C# 3.0
	Matthew MacDonald Paperback, 1498 pages 235 x 235 x 52mm (L x W x H) ISBN-13: 978-1-59059-893-1 29 October 2007 Published by APress

In due time I'll write more about these books.

VB2008 Gems

2007-11-26T09:15:00Z

Amanda Silver from The Visual Basic Team recently blogged about Hidden Gems in Visual Basic 2008.

<personal note>Call me a die hard VB developer. You see every time I start a new project I tell myself this one will be in C# but it always ends up as a VB.Net one.</personal note>

A nice picture I found on Wikipedia explaining .Net 3.0

2007-09-20T13:22:11Z

WCF is a new communication subsystem to enable applications, in one machine or across multiple machines connected by a network, to communicate.

WPF is the graphical subsystem feature of the .NET Framework 3.0 and is directly related to XAML.

WCS is a framework developed by Microsoft which securely stores digital identities of a person, and provides a unified interface for choosing the identity for a particular transaction, such as logging in to a website.

WWF is a Microsoft technology for defining, executing, and managing workflows.

Non Functional Requirements Checklist / Template

2007-09-10T09:29:00Z

1. USABILITY

Usability is a measure of how well the software supports the execution of user tasks. Key factors contributing to usability are the presentation of information and the management of user interaction. Usability includes two other measures, affordance and accessibility.

1.1 Affordance is a measure of the cost of learning to be productive with a user interface [Nor]. A user interface may be highly usable once it has been learned, but difficult to learn. The well-known EMACS text editor is an example of such an interface. A user interface that is highly intuitive, and therefore easy to learn, is said to have high affordance.

1.2 Accessibility is a measure of how broad a pool of users can interact effectively with the user interface. A highly accessible user interface can accommodate the needs of users with a wide variety of requirements, for example by providing interface mechanisms to help users with physical impairments, or by providing localized versions of the user interface.

2. RELIABILITY

Reliability is a measure of the frequency and severity of defects encountered during normal operation of the software. The more severe the defects and the more frequently they are encountered, the less reliable the software. Three related measures are fault tolerance, robustness and security.

2.1 Fault tolerance is a measure of how well the system can maintain normal operation when defects are encountered. Examples of fault tolerance in distributed business applications include recovering from failed transactions and routing tasks to other resources when the original resources are incapacitated.

2.2 Robustness is a measure of how well the system avoids failures when confronted with invalid data or incorrect usage.

2.3 Security is a measure of how well the system avoids a specific type of failure, namely the unauthorized exposure of the processes and entities manipulated by the system.

3. PERFORMANCE

Performance is a measure of how quickly the system responds to stimuli, and how well it utilizes resources in providing that response. Performance is often defined in terms of latency, throughput, efficiency and scalability.

3.1 Latency is a measure of the amount of time that elapses in performing a given operation under a given operating load.

3.2 Throughput is a measure of how many operations can be performed in a given amount of time under a given operating load.

3.3 Efficiency is a measure of how many resources must be consumed by the software to provide acceptable latency and throughput under a given operating load.

3.4 Scalability is a measure of how many additional resources must be consumed by the software to maintain acceptable latency and throughput with increasing load.

4. SUPPORTABILITY

Supportability is a measure of the cost of supporting the software after it has been delivered to the customer. Measures that contribute to supportability include maintainability, malleability, extensibility, portability, interoperability and testability.

4.1 Maintainability is a measure of how easy it is to correct defects in the software. This is determined by the degree of cohesion within the components, and by how well features are localized within the software.

4.2 Malleability is a measure of how easy is to modify the software to accommodate changes in requirements. This is determined by the degree of encapsulation of the components, and by how well they can vary independently of one another.

4.3 Extensibility is a measure of how easy it is to replace existing parts of the software, and how easy it is to add new functionality. This is determined by the degree of coupling among the components. When components are highly coupled, it is difficult to replace one without affecting the others.

4.4 Portability is a measure of how easy it is to adapt the software to run on different platforms. This is determined by how well platform dependencies are localized and encapsulated within the software.

4.5 Interoperability is a measure of how easy it is to compose the software with other systems. This is determined by how well the software exposes its functionality through programmatic interfaces and how much context must be maintained by the other systems to use those interfaces.

4.6 Testability is a measure of how easy it is to design tests that exercise the features of the software to expose defects. This is related to the level of factoring of the features. When features are highly factored, they are easier to access in isolation, and therefore to test independently, and defects are easier to isolate.

Reference

J. Greenfield, K. Short. Software Factories: Assembling Applications with Patterns, Models, Frameworks, and Tools. John Wiley & Sons, 2004 (Chapter 2)

R. Grady. Practical Software Metrics for Project Management and Process Improvement. Prentice Hall, 1992

F. Buschmann,R. Meunier,H. Rohnert,P. Sommerlad,M. Stal. Pattern-Oriented Software Architecture, Volume 1. A System Of Patterns. Wiley Publishing, Inc., 1996

Head First Object Oriented Analysis and Design book review

2007-09-06T09:25:00Z

A while back a very nice lady at O'Reilly publishers, Kathryn Barrett, send me a book from the Head First series. Head First Object Oriented Analysis and Design is a very nice book for new analysts because it covers most of the basic's subjects. Topic's includes requirement gathering, analysis and design, architecture, design principals, iterations, testing and lifecycles.

If you are used to reading Eric Evans and Martin Folwer this book maybe not be for you because it does not cover the details but if you are after the basic's this is a very nice place to start.

Great software in 3 easy steps

Make sure your software does what the customer wants it to do.
Apply basic OO principals to add flexibility
Strive for a maintainable, reusable design

Gathering requirements

The best way to get good requirements is to understand what a system is suppose to do. (p.67)

Requirements change

Requirements always change. If you've got good use cases, though, you cab usually change your software quickly to adjust to those new requirements. (p.115)

Analysis

A good use case clearly and accurately explains what a system does, in language that's easily understood. (p.151)

Design

A cohesive class does one thing really well and does not try to do or be something else. (p.269)

Solving really big problems

You can solve a big problem by breaking it into lots of functional pieces and the working on each of those pieces individually. (p.281)

Iterating and testing

Good software is build literately. Analysis, design and then iterate again, working on smaller and smaller parts of your app. (p.451)
Each time you iterate, reevaluate your design decisions and don't be afraid to change something if it makes sense for your design. (p.451)

Design patterns

Design patterns help you recognize and implement good solutions to common problems. (p.563)
Anti patterns are about recognizing and avoiding bad solutions to common problems. (p.563)

Head First Object-Oriented Analysis and Design

Written by Brett D. McLaughlin, Gary Pollice and David West

Published by O'Reilly

ISDN-10 0-596-00867-8

Where is the SOAP?

2007-08-29T21:28:00Z

While busy playing around with .Net Framework 3.5 I noticed to my surprise that I could not find the SoapFormatter. Am I missing something? Or have Microsoft decided to go only with XMLSerializer for Framework 3.5 serialization to XML? Which make sort of sense if you read what this guy have to say about comparing the two.

Spring.Net and AOP

2007-08-22T07:37:14Z

One of Spring.Net claims to fame is it's implemetation of AOP (Aspect Oriented Programming). Read about it here and see how they do it here.

Spring.NET is an open source application framework that makes building enterprise .NET applications easier. Providing components based on proven design patterns that can be integrated into all tiers of your application architecture, Spring helps increase development productivity and improve application quality and performance. Downloads are available through the SourceForge project page.

Aspect-oriented programming (AOP) attempt to aid programmers in the separation of concerns, specifically cross-cutting concerns, as an advance in modularization. (Wikipedia)

On Methods, Process and Models

2007-08-16T11:06:00Z

Thoughts about Methods, Process and Models taken from the book Microsoft Object Thinking by David West. (See chapter 6)

All methods are someone else’s idea about what you should do when you develop software. It may be useful, from time to time, to borrow from those ideas and integrate them into your own style. It is essential, however, to transcend any method, even your own idiosyncratic method, and “just do it.”
Software development is like riding a surfboard—there is no process that will assure a successful ride, nor is there any process that will assure that you will interact propitiously with the other surfers sharing the same wave. Published processes, like published methods, provide observational data from which you can learn and thereby improve your innate abilities—just as observation of master surfers enables you to improve yourself.
No model has any value other than to assist in object thinking and to provide a means for interpersonal communication. If you can model your objects and your scenarios in your head while engaged in writing code, and if those mental models are consistent with object thinking, great! No need to write them down. If you and your colleagues use a visual model on a whiteboard as an aid in talking about scenarios and in clarifying your collective thinking about those scenarios, and you erase the board when you’re done meeting, also great! If your models are crudely drawn and use only a subset of the syntax defined here (or a completely different syntax that you and your colleagues collectively agree upon), still great! Model when you must, what you must, and only what you must.

Microsoft ObjectThinkingDavid West PUBLISHED BY
Microsoft Press
A Division of Microsoft Corporation
One Microsoft Way
Redmond, Washington 98052-6399

Data Access Tutorials for ASP.Net 2.0

2007-08-15T11:10:05Z

Today I discovered a treasure chest of tutorials written by Scott Mitchell for ASP.Net 2.0. Go have a look here.

Code samples are provided in VB.Net and C#.