Interest in cognitive or mental workload has over the last couple of years increased drastically from a manufacturing application perspective. More and more, people are becoming aware of the cognitive limitations that may have great impact on production outcome. The more easily observable area of physical ergonomics has been successfully investigated for a long time and it would seem as though focus has broadened to also include cognitive ergonomics. Considering the effects that a large cognitive load has on human performance, knowledge regarding the role of the cognizing human in a manufacturing environment could potentially have significant effect on production outcome (i.e. quality and productivity). With this in mind, developing and using methods and tools for assessment of the cognitive burden associated with particular tasks or workstations should be and is of substantial interest to the manufacturing industry. Whatever assessment methods exist in the scientific literature today are almost exclusively expert tools where significant expertise in the area of cognitive ergonomics/psychology/science is required. This paper reports parts of the development process and initial version of a non-expert tool for assessment of cognitive load in manual production environments, primarily manual assembly.