Dessler (2017) says an employee needs to establish a prima facie case of discrimination which then shifts the burden of proof to the employer. one of the precedents set by the court ruling in Griggs v. Duke Power Company established business necessity as a possible defense in these cases. Other sources say that employers that prove business necessity may still not win the case if it is shown that alternative practices could yield "lesser disparate impact." This is an exciting addition, but it raises some questions. Since the burden of proof lies with the employer, are they obligated to research alternative practices, or does the plaintiff need to present alternatives as proof? Is "lesser disparate impact" any more acceptable? If "lesser impact" alternatives exist but were not chosen, does that imply the employer may be guilty of disparate treatment?