Feeds

Of software bugs and learning curves

Testing as learning

The Power of One Brief: Top reasons to choose HP BladeSystem

Shaker Loops

Successful design is inevitably incremental, although some steps might be larger than others. It inevitably involves acceptance of change, and therefore renewal and removal, rather than the obstruction of change. Of course, just to be clear, acceptance of change is not the same as an absence of stability. And, to take us back to where we started, successful design does not rely on software defects as its primary source of feedback.

Design is both a feedforward and a feedback process, which makes it a dialogue: between people; between people and the design; between people and the results of the design. This is where learning fits in. So there is a need to shorten long feedback loops, but there is also a need to increase signal to noise ratio by reducing interference — continuous unregulated feedback is noisy rather than helpful.

To take an example people often associate with the issue of bugs, consider the role of testing in software development. Is testing, as is often articulated, concerned only with the discovery of defects in software as built? Is testing, as is sometimes assumed, the sole preserve of a testing department and individuals with "tester" in their job title? Is testing, as expressed in many traditional development processes, something that necessarily falls in the closing phases of the lifecycle after all the "development" has been done?

If testing is divorced from other activities in software development and placed towards the end of the development lifecycle, carried out only by individuals who were not involved in the design of the system, its main contribution to the software is pretty much limited to one thing: defect reports. This is certainly better than nothing (and certainly better than many companies manage), but it represents a wasted opportunity for learning and a poor distribution of responsibilities, schedule and money. In such lifecycles testing is consigned to play a passive rather than active role, a role that cannot influence the framing of requirements, the design decisions, the coding guidelines or the team and its individuals until after the fact. If there is any genuine learning, it will typically be localised and lost or, at best, deferred to the next project.

As I said, a wasted opportunity. It is generally considered wiser to close the stable door before the horses bolt. Testing offers a form of empirical feedback that can be used to drive design, clarifying requirements and providing a health check for code.

Running testing along the main axis of software development and across more than one development role shakes up the pipeline model of traditional development processes. It closes many of the open feedback loops and shortens many of the others, while at the same time ensuring that the signal is stronger than the noise. Instead of treating testing as a critical passenger, shoved into the backseat, it becomes an informative driver. Testing ceases merely to be a synonym for bug hunting and becomes a proactive form of learning. ®

This article originally appeared in Application Development Advisor.

Kevlin Henney is an independent software development consultant and trainer. He can be reached at http://www.curbralan.com

Securing Web Applications Made Simple and Scalable

More from The Register

next story
Apple fanbois SCREAM as update BRICKS their Macbook Airs
Ragegasm spills over as firmware upgrade kills machines
HIDDEN packet sniffer spy tech in MILLIONS of iPhones, iPads – expert
Don't panic though – Apple's backdoor is not wide open to all, guru tells us
NO MORE ALL CAPS and other pleasures of Visual Studio 14
Unpicking a packed preview that breaks down ASP.NET
Captain Kirk sets phaser to SLAUGHTER after trying new Facebook app
William Shatner less-than-impressed by Zuck's celebrity-only app
Cheer up, Nokia fans. It can start making mobes again in 18 months
The real winner of the Nokia sale is *drumroll* ... Nokia
Mozilla fixes CRITICAL security holes in Firefox, urges v31 upgrade
Misc memory hazards 'could be exploited' - and guess what, one's a Javascript vuln
EU dons gloves, pokes Google's deals with Android mobe makers
El Reg cops a squint at investigatory letters
Chrome browser has been DRAINING PC batteries for YEARS
Google is only now fixing ancient, energy-sapping bug
prev story

Whitepapers

Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Reducing security risks from open source software
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.