Why flexibility? Need for flexibility: The concept of flexibility has permeated much of current thinking in human resource management, justifying the recent evolution of more flexible and variable work models. Its need arises from the following: The changing business environment - highly competitive "global" product markets, increasingly rapid advances in information and communication technologies (ICT) and an intensity increasing capitalization of production. A changing social environment – ​​for example, increasing women's participation rates and the trend toward early retirement and increasing divorce rates. Government policy environment – ​​a desire to reduce unemployment and make the economy attractive to foreign investment as a source of employment and long-term growth. Flexible business model: Atkinson and Meager's model of "business flexibility" identifies four types of flexibility sought by businesses:1. Functional: This refers to a company's ability to adjust and deploy the skills of its employees to meet the tasks required by its changing workload and production methods. This requires versatility / dual skills / dismantling traditional rigidities between professional groups (horizontal and vertical flexibility). The goal is to improve efficiency and reduce costs. This is a central area of ​​traditional conflict within the division of labor between distinct skilled groups and between the skilled and the unskilled (Penn, 1985).2. Digital: This refers to a company's ability to adjust the level of labor to respond to fluctuations in production. There is an increasing use of part-time workers, temporary staff, short-term staff, job sharers and agency workers. There is a contrast between the permanent “core” workforce and the non-permanent “peripheral” workforce. The general idea is that an increasing mix of non-standard forms of employment will be more efficient and cheaper.3. Distancing strategies: This refers to the increased reliance on other businesses that perform non-essential activities such as catering, cleaning and transportation. Such a strategy will cost less.4. Financial: This refers to gaining flexibility through pay and reward structure.5. Temporal flexibility: it concerns the structure of hours worked and is linked to the requirements of the company. Seasonal or on-demand work is provided leading to Flexi-time systems. In addition, annual time contracts are awarded with an increase in evening work. These flexibilities are achieved through a division of employees into: • Core workforce: The core group is made up of highly skilled, well-paid workers recruited from the primary labor market. These workers are expected to provide functional flexibility. Workers in the core group have better career and promotion prospects and generally benefit from comprehensive training and development. • Peripheral workforce: The peripheral group consists of two types of groups..