May 12th, 2004 — Improving Testability — Dave Catlett

Published: Sat 01 May 2004
By nwcpp

In 2004.


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Redmond, WA 98052

Improving Testability: Decreasing the cost of developing and maintaining software while increasing quality

Thorough testing can be expensive in terms of time and resources, especially if the software component or the systems it interacts with are difficult to test. It is necessary though in order to deliver high quality software that meets the user’s needs. By designing testability features into the component, not only is testing easier, it helps enforce good design principles, it makes diagnosing unexpected behavior go faster, it can improve manageability of the component, and it reduces the cost of supporting the software after it “ships.” In short, it increases quality while reducing cost.

Determining testability can be achieved using the SOCK analysis method, where S=Simplicity, O=Observability, C=Control, and K=Knowledge of expected results. For example, using an observer design pattern class to increase observability will not only make it easier for an automated test to determine pass or fail at any given point in time, it will provide a history of events making diagnosis of a bug much easier both during the development cycle and by the support team after the software is shipped. We will go through this and other practical examples of how to improve testability by improve in each area of SOCK.


Dave Catlett has been testing software and developing people, tools and techniques for testing software for over 12 years. In his current role as Test Architect for the Microsoft Windows Networking & Devices group, Dave has been researching and implementing methods to decrease the costs while increasing the quality of software throughout the engineering lifecycle. Dave holds a B.S. in Computer Science/Math from the University of Puget Sound and more importantly is a husband to Erika and dad to Josh, Emilie and Sara. He’s also pursuing a career as world-famous groundskeeper for the Eastlake Little League Dodgers of which his son is a starting pitcher. Go blue!

Click here to download the slides from the presentation