In factories where products are mass-produced, it's extremely important to know how long the human workers take to perform certain tasks. This not only allows the pace of the assembly line to be set, but it also allows factory owners to identify time-wasting problems such as superfluous movements, overly frequent tool changes, or impractically-located components. Typically, workers are periodically timed by a stopwatch-wielding supervisor, or using a timer that they start and stop themselves. A new wearable time-keeping system, however, promises more accurate readings.

According to Germany's Fraunhofer Institute for Factory Operation and Automation, there are at least two main drawbacks to existing time-keeping methods. For one thing, workers tend to be nervous when being monitored by someone else, and will work faster than normal, possibly also making more mistakes. Additionally, a supervisor timing their employees is being taken away from other duties, decreasing efficiency.

Fraunhofer's new system, designed under contract for engineering firm DR. GRUENDLER, incorporates two sleeves worn by the worker. Each sleeve contains three matchbox-sized sensors, located on the upper and lower arm, and the hand. These measure the acceleration and angular velocities of arms and hands in the X, Y and Z axes. After initially being "taught" by the user, the hardware can identify and isolate actions such as reaching, grasping, setting up, joining, checking or releasing.

The system doesn't require any extra infrastructure (unlike GPS), and allows multiple workers - wearing multiple sets of sleeves - to be timed simultaneously. Once the data has been gathered, a PC application reconstructs the motion sequences, breaking them down into precisely-timed individual actions.

Presently, the Fraunhofer system is applicable to assembly jobs at workplaces where employees are seated. Down the road, however, there are plans for it to be adapted for use with standing and moving employees, and for it to be able to detect their posture.