What would cause a business to change its product or service design?

CHANGES IN THE MARKET would cause a business to change its product or service design. Change in the market may affect either the demand or the supply either negatively or positively. Other factors that can cause change in the market include: increase in the interest or exchange rate, new technology and innovations, emergence of new competitors, etc. 

The advantage of administering personality tests on employees is that it will allow the employer to know the mindset and personality of the employee. this will allow the employer to at least have an idea as to how the employee works and how his attitude in the workplace. the disadvantage is that it may make the employee a little anxious as to whether he would meet the personality requirements of the employer and whether he would be able to retain the job or not.