Threat classification is extremely important for individuals and organizations, as it is an important step towards realization of information security. In fact, with the progress of information technologies (IT) security becomes a major challenge for organizations which are vulnerable to many types of insiders and outsiders security threats. The paper deals with threats classification models in order to help managers to define threat characteristics and then protect their assets from them. Existing threats classification models are non complete and present non orthogonal threats classes. The aim of this paper is to suggest a scalable and complete approach that classifies security threat in orthogonal way.

In earlier works, we present the quantification of security threats of e-learning systems using an economic measure abridged by MFC (Mean Failure Cost). It allows an analyst to estimate the security of a system in terms of the loss that each stakeholder stands to sustain as a result of security breakdowns. This paper provides an understanding of the security problems and risks related to e-learning systems. Then to control the MFC matrix, in particular its first matrix (the stake matrix) and to reduce its values we propose a classification of security problems versus the security requirements taxonomy of the MFC cyber-security model. The strength of the paper is in designing and deploying security measures and solutions to requirements.

An empirical study of the management of software maintenance is presented, based on completion of an earlier study. The survey at hand has been conducted by means of live interviews with analysts and software managers, using a translated version of B.P. Lientz and E.B. Swanson's (1978) survey form (slightly adjusted at times to take into account a difference of data processing culture). The authors accumulated a total of 150 completed survey forms, properly distributed on the various sectors of the Tunisian data processing industry. For the sake of comparison or confirmation, the authors mention a similar study that was carried out by one of the authors with some companies in Algeria. This study covers a total of sixty surveys, taken in 1988 and 1989. The final results are presented. The issues discussed are scale of effect issues, organizational issues, productivity technique issues and problem area issues.>

A recent statistical study of the various economic aspects of software maintenance management in Tunisia is presented. The study confirms a well-known results, that software maintenance is very time consuming. It was also found that software maintenance escapes the software manager's notice. In the study, only one in ten managers considers maintenance problems important or very important. In addition, it was shown that the longevity of software applications does not depend on the data processing environment. It is concluded that software maintenance is controllable. Combined with appropriately calibrated cost-estimation techniques, organizational steps developed by the community of software practitioners can be arranged into an integrated policy for software maintenance.>