The importance to be able to work is recognised as one of the United Nation's Sustainable Development Goals. Occupational therapists working in vocational rehabilitation require cost effective, valid, and reliable tests that offer flexibility during the work evaluation process. The use of self-developed work samples standardized using Modular Arrangement of Predetermined Time Standards (MODAPTS) as an objective measure of work speed could meet this need. Evaluate the face, content, and criterion validity of MODAPTS work samples to assess work speed. We conducted a quantitative cross-sectional, descriptive study. Occupational therapists completed electronic surveys to evaluate face and content validity. We evaluated criterion validity during a multiphase process that involved a realist synthesis, online survey, and comparing MODAPTS to Methods Time Management (MTM) time standards using three work samples that measured work speed. MODAPTS had good face validity for measuring work speed. We also confirmed the content and criterion validity of codes used to analyse basic movement and handling of smaller and larger articles as well as other body actions. MODAPTS demonstrated adequate face, content and criterion validity of tasks involving basic movements, handling of articles and other body actions.