Employees were given 14 minutes between each shift to punch the time clock, walk to their respective workbench and prepare for work.

Seven employees and their labor union (represented by Edward Lamb) brought a class action suit under Section 16(b) of the FLSA alleging that the employer's calculations did not accurately reflect the time actually worked and that they were deprived of the proper amount of overtime compensation.

The special master recommended that the case be dismissed because the employees did not establish by a preponderance of evidence a violation of the Act.

The court of appeals further held that the burden rested upon the employees to prove by a preponderance of the evidence that they did not receive the wages to which they were entitled.

[4] The majority held that the court of appeals and the special master had imposed an improper standard of proof on the employees.

Where the employer has failed to keep accurate or adequate records, Justice Murphy argued, the law does not deny recovery on the ground that the employee is unable to prove the precise extent of uncompensated work.

Such a ruling, Murphy noted, would create a strong disincentive for employers to keep any records at all and shift the burden back onto the employee.

But the majority held that the employer required workers to be on the premises prior and subsequent to the scheduled working hours.

Murphy dismissed arguments against vagueness in determining the compensatory award by advocating a de minimis approach.

He thought not: "Split-second absurdities are not justified by the actualities of working conditions or by the policy of the Fair Labor Standards Act.

"[7] Murphy reasoned, however, that the evidence clearly showed that workers did spend a "substantial measure" of time engaged in prep work.

There is no evidence that Congress meant to redefine this common term and to set aside long established contracts or customs which had absorbed in the rate of pay of the respective jobs recognition of whatever preliminary activities might be required of the worker by that particular job.... "Workweek" is a simple term used by Congress in accordance with the common understanding of it.

For this Court to include in it items that have been customarily and generally absorbed in the rate of pay but excluded from measured working time is not justified in the absence of affirmative legislative action.

However, Section 4 of the 1947 Act required that the determination of whether time spent in preliminary or postliminary activities was "work" under the FLSA was to be based solely on contract, custom, or practice.

The Supreme Court attempted to clarify the issue in Steiner v. Mitchell, 350 U.S. 247 (1956), by ruling that activities which were "integral" to work (such as the donning of protective clothing) were compensable under the FLSA and Portal-to-Portal Act.

Clemens Pottery in affirming the right of pork processing plant workers in using statistics to support their back-wage claims for time spent in donning protective clothing and equipment while at work.