Ergolight is a methodology for usability and resilience assurance, by incorporating human factors in the system design.


Ergolight has been developed since 1997, using special tools for tracking and analyzing the user behavior. The tools were based on a model of the users' behavior, incorporating descriptions of the user faults.

View the historic Ergolight web site



The first project was a program installed on Windows platforms, featuring:

The user's activities were synchronized with the user's intentions by time stamps.

The method used in this project was disclosed in the CHI 1998 conference.

Today it is used in ErgoSafe, in the form of guidelines for in-house resilience testing.


The second project was a variant of GUI-Tester, facilitating the work of usability testers in usability labs. In addition to the features of GUI-Tester, LabTester enabled usability testers to enter the user's intentions instead of the users, and to manage the tests by task lists.

Today, it is used in ErgoSafe, in the form of guidelines for resilience-oriented usability testing in traditional settings.


The third project targeted managers of web sites. It analyzed log files of the site visitors, stored on the servers. The analysis was by statistics of recurring activity, based on a model of site navigation.

The method for the statistical analysis was disclosed in a book about eCommerce research.

The methods of WebTester are used today for agile testing of the effectiveness of web sites, installed on Cloud and Edge mini-servers.


The fourth project was a program targeting specific problems of user-machine coordination. Contrary to the first three projects, which targeted the testing stage, this program was used at the design stage, to identify error-prone controls. The program features included:

This method is used today in ErgoSafe, in a form of guidelines for assuring operator-machine cooperation.


The fifth project is actually a set of applications of a methodology for alarm design. Common alarm controllers, which enable tradeoff of missed vs. false alarms, by controlling the alarm threshold. The method used by AlarmController is based on alarm protocols, which reduces the rate of nuisance while in alarm condition.

The alarm controller was developed by building prototypes for three applications:

Today this method is used in ErgoSafe, in a form of guidelines for alarm design.


All the projects were implemented on Windows platforms, using Delphi.


The most recent project is a guide for resilience assurance. The guide targets system designers, who need to mitigate the risks of mistakes when operating in exceptional situations.

This project was developed with the support of the Gordon Center for System Engineering.