"The water spider is a term that refers to a specific person whose main job is to make sure that materials are supplied to where they are needed. While this is mainly a material replenishment position, it offers a bit more flexibility, and some additional benefits if well-implemented. The rationale behind having such a person is to allow the rest of the personnel to devote their full attention to tasks that add value to the process. This also highlights how much transportation waste and inefficiency exists in the process by isolating it all into one or more positions."

https://www.shmula.com/what-is-the-role-of-the-waterspider-i...

I found this:

https://www.flexpipeinc.com/ca_en/role_of_waterspider/

> Water spider is a term that refers to a specific person whose main job is to take care of intermittent tasks such as supplying material at workstations.

According to https://kanbantool.com/kanban-guide/water-spider:

> A water spider is a Lean production personnel role centered around timely and accurate stock replenishment. The water spider team member is similar to a mobile Kanban system that refills the production line with the required materials to maintain a steady flow.

I had not heard the term either. Based on what others have written here, the position sounds similar to, but not exactly the same as, what manufacturing companies call an expeditor: A person assigned to the manufacturing floor who gets hot (late) orders finished and shipped as soon as possible.

It’s the only species of spider known to live entirely underwater.