What is the role of the Waterspider in a lean manufacturing structure

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.

Like during surgery the assisting person is like a Water Spider, they allow the surgeon to perform the added value task with no distraction.

The key to adding value tasks without distractions
The key to adding value tasks without distractions

The rationale behind the water spider in the factory is similar where it allows the rest of the personnel to devote their full attention to added value tasks.

The Water Spider position is often confused with a simple material handler but in a lean manufacturing layout, a Water Spider must be intimate with the process or work cell they support, not just a pick-up-and-drop-off handler.

The tasks of a water Spider

Water Spider is the go-to person when there is an out-of-cycle task, for example:

  • supply raw materials and parts,
  • transport finished goods away from the work area,
  • remove waste,
  • move Kanban cards,
  • update status boards,
  • pack materials to be taken away,
  • replace tools
  • help with changeovers,
  • keep an eye on less experienced personnel.
Water Spider is the go-to person in a well organized area
Water Spider is the go-to person in a well organized area


A water Spider must be intimate with the process or work cell they support
A water Spider must be intimate with the process or work cell they support

Water Spider needs to make sure that the production flow is uninterrupted, and workers are only devote added value tasks.

When a particular worker doesn’t have to take care of auxiliary tasks, they can concentrate on their own productivity. They can become more efficient at adding value.

They should visit the workstations and operators in the same order and at similar intervals. The speed and frequency of their rounds should be dictated by the needs of the process.

The analogy with the insect

Water Spider is mizusumashi in Japanese and is often used even in English meaning “make water cleaner” or “purify water”.

Water spiders are representing by Water beetle, notable for their divided eyes.
Water spiders are representing by Water beetle, notable for their divided eyes.

Water spiders are representing by Water beetle, notable for their divided eyes and that dives into freshwater but does not stay into water. The water spider dives into the process to get close to the cell, even goes into the cell to do occasional relief work for operators. Specifically, the whirligig beetle is known for their habit of swimming rapidly in circles… and for their gregarious behaviour…and are also notable for their divided eyes which are believed to enable them to see both above and below water”.

And If employees don’t like the name why not using Point of use Provider.

How to boost productivity

While some floor managers might feel the urge to put a not-so-skilled worker in this position, this is not a good idea:

In order for a water spider to really boost productivity, they need to have a great working understanding of the whole process and need to be able to read the whole workspace.

Here are some important requirements for the job

They should be helpful at every workstation they service, and this requires knowledge of all processes and great work experience.

  • They should be first to notice when problems arise, and this requires good working relationships with management, to raise the issue.
  • They should help with the unexpected and know about the challenges faced in the day-to-day work at stations and this require to communicate well, gets along with everyone to help
  • They should move, lift, transport and do a lot of walking required for the water spider to be in good shape to walk, lift, and move material.

Learn more on how to maximize productivity with the Andon system. A great way to quickly pinpoint issues at manually operated workstations, improve response time, and reduce downtime is through an Andon system.

The Japanese Influence

Taiichi Ohno, the founder of the Lean Approach
Taiichi Ohno, the founder of the Lean Approach

Some Senseis say that Water Spider role is a “rite of passage” to becoming a supervisor.

This is why it makes a lot of sense, to treat the position as a way to groom a future team leader, supervisor or manager, instead of a “go-fer” or “catch-all” job.

Elements of success

  • Both the water spider and the other workers’ Everyone should have a clear idea of what the water spider is there to do and not to do. : Managers might view water spiders as auxiliary, and therefore secondary in priority.
  • This might lead to assigning them fill-in tasks, which might end up hurting the productivity of the whole facility. Don’t treat the water strider as a floater, or as an excess person.
  • Depending on the size of the work area and the material demands, a water spider may not perform that role full time but their rounds should still be made at regular intervals, though, to keep operators from running out of parts.
  • A clear process flow and defined work sequence (clear flowing water) is required to design the workload of the Water Spider position.
  • To begin, the role should be tested out on a small scale to get a feel for how to use this position. The key is structure. They must make the rounds in sync with the pace of production.
  • You might find that Water Spider might do too many empty rounds at first and feel that there is the inefficiency to work on. However, you should try to optimize the system first not the water spider time. It can be deemed acceptable as long as the water spider manages to help boost the efficiency of the whole operation.

Read on to learn how a modular pipe handling system helped Hologic increase its productivity by 25%.

Extra recommendations!

Spaghetti diagram
Spaghetti diagram
  • For every workstation on the assembly line create a spaghetti diagram of the stock replenishment path
  • Work on small and regular milk runs
  • Clock the water spider with a pedometer to log the typical distance travel and ask how this could be improved
  • Supermarket should be not too far from the assembly line. There may be more than one supermarket for longer lines.
  • An exhausted water spider is a good sign that something is wrong. And at this point, he might now be able to see clearly.

You should be able to see how having a well-functioning water spider can boost overall efficiency and potentially calculate an ROI to present to management. Furthermore, isolating the auxiliary tasks mostly transportation and movement waste in a single place will help to examine them and possibly reduce or eliminate them.



Flexpipe Modular industrial pipe racking system can help you with implementing continuous improvement principles. Your team’s creativity can result in a 10% increase in productivity per year. It has been a proven system for more than 50 years now.

See how the modular system improve operational efficiency while saving time in manufacturing processes at Waterax.


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