Software QA 101: The Basics of Testing
By: Sue Hildreth
The testing phase of software development often gets short shrift by developers and IT managers. Yet testing is the only way to determine whether an application will function properly before it is deployed. In this article, Sue Hildreth offers an overview of the why and how of software testing.
Although it doesn't get a lot of press, testing is arguably the most important phase in any software development project. Certainly testing is the best—the only—way to know whether your project or product is destined for success or doomed to failure before it goes live. The U.S. Commerce Department has estimated that buggy software costs nearly $60 billion annually, and that at least $22.2 billion worth of those bugs could have been prevented with more thorough testing.
And although you might like to think that your newly coded application is virtually bug-free, we all know by now that it just ain't so. Sandra Tise of Empirix, a testing tool maker, notes that there's simply no such thing as an error-free application: "Frankly, I know of no software test that I've done that has come back perfect."
There are many, many different ways to test software, but most tend to fall into two broad categories: functional testing and performance testing.
Functional testing covers how well the system executes the functions it is supposed to execute—including user commands, data manipulation, searches and business processes, user screens, and integrations. Functional testing covers the obvious surface type of functions, as well as the back-end operations (such as security and how upgrades affect the system).
Arthur Povlot of Tescom Software Systems Testing, says:
"If you have an old Vantive [CRM] system, and you have to migrate all your information to a new [CRM] system, that is where a lot of the functional issues will occur. You have to do that migration and then verify that the information is there [in the new system]."
Although functional testing is often done toward the end of the development cycle, it can—and should, say experts—be started much earlier. Individual components and processes can be tested early on, even before it's possible to do functional testing on the entire system.
The Aberdeen Group, a Boston-based analyst firm, has noted that because today's applications require constant updating and redeployment, IT needs to think in terms of testing throughout the entire life-cycle of an application. In a 2003 InSight report, it noted that
"...cross-lifecycle software testing has a significant positive impact, not only on software quality but also on timely application delivery and ongoing maintenance costs, especially when it is integrated early in the application development cycle."
Performance testing is perhaps the biggest area of testing. Dan Koloski, the product manager for Empirix, describes the different types of performance testing that can be done:
Classic performance testing, which measures response times and transaction rates
Load testing, which measures the system's ability to handle varied workloads
Stress testing, which looks for errors produced by low resources or competition for resources
Volume testing, which subjects the software to larger and larger amounts of data to determine its point of failure
According to Povlot, typical areas of failure in performance testing of enterprise applications such as a CRM system fall into categories such as inadequate bandwidth, hardware issues, volume and size of transactions the system can handle, and problems with the database.
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