What is the Role of the Water Spider in Lean Manufacturing?
There are different ways to handle parts and materials when organizing your factory floor, and one interesting options that is part of the Lean Manufacturing methodology is the “water spider.”
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.
To the untrained eye, a water spider might look like a free floater that does a variety of tasks, besides making sure materials are properly stocked everywhere. It’s easy to get the misleading feeling that this is a bit of a chaotic role, but this could not be further from the truth. While the water spider needs to make sure that the production flow is uninterrupted and unobstructed, they should also follow a standardized process themselves.
The job of the water spider is NOT to increase variability by constantly improvising and by being excessively flexible, but to minimize variation for everybody else on the production floor or within the process. The first thing to put on standard work is their physical route. 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, and its timing should be designed to fit with what is needed. Everybody should be constantly supplied, so the value-adding flow is never interrupted, while the water spider themselves should not make too many excessive rounds (except for special situations).
The water spider should have a clear set of tasks described in their process. They don’t have to be limited to just bringing and taking materials. The position can also include some form of supervision and handling other auxiliary tasks. A water spider can supply raw materials and parts, transport finished products away from the work area, remove waste, move Kanban cards, update status boards, pack materials to be taken away, or even keep an eye on less experienced personnel. Regardless of the exact things the water spider is tasked with, each one should be part of their standardized working process. Both the water spider and the other workers should have a clear idea of what the water spider is there to do and not to do.
Role and Main Benefits
The main reason to implement a water spider is to decrease variation for everybody else. When a particular worker doesn’t have to take care of auxiliary tasks, they can concentrate on their own productivity. When they are relieved from those additional parts of their job, they can become more efficient at adding value, and could avoid wasting their time and attention. This makes the process increasingly leaner (for everyone except the water spider), and it’s easy to see how having a well-functioning water spider can boost overall efficiency. Simply stated, it makes everybody’s job more value-added, and therefore easier to standardize and optimize.
While some floor managers might feel the urge to put a not-so-skilled worker in this position, this is not a good idea by any means. In order for a water spider to really boost productivity, they need to have a working understanding of the whole process, and need to be able to read the whole work space. They should be helpful at every workstation they service, and this requires knowledge and experience.
Additionally, the work the water spider does is quite time sensitive, and they should be able to remain on pace throughout the whole workday. When a water spider is underperforming, they can put the whole process in jeopardy by introducing blockages, shortages and general waste. That’s why a person that is going to take this position needs to develop a thorough understanding of the whole area they will be servicing. They will also be the first one to notice when problems arise, and should have a good working relationship with management, to raise the issue so it gets proper attention.
As the water spider’s rounds are time-sensitive, and timing should be part of their standardization, they might sometimes end up making too many empty rounds. This is an inefficiency that is often easy to overlook, but it should be addressed. Of course, as the water spider’s main role is to keep the whole process ticking, a small amount of inefficiency is to be expected. Remember, they are trying to optimize the system, not their own time, so that will naturally lead to some inefficiency. It can be deemed acceptable as long as the water spider manages to help boost the efficiency of the whole operation.
Additionally, sometimes 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. That’s why standardization is so important as it keeps the role focused on material handling.
Possibility for Growth
While the water spider position requires some experience and learning, it also presents a significant opportunity for professional growth, especially with Lean and Six Sigma. While working at this position, a person could learn a lot about how the factory floor of the company actually operates, In addition, they can learn about the actual people taking part in the process, and about the challenges faced in the day-to-day work. 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. Selecting an individual with significant potential will help them do this pivotal job well, but will also put them in a good position to be of even greater value in the future. In addition, they will be a great resource as a lean event facilitator, able to see the whole system, and highlight how each workstation fits within the system. That is why a good working relationship with workers and managers is important.
Implementing a water spider is a great way to put the value and principles of Lean Manufacturing into practice. It allows complex production processes to be optimized and boosted by decreasing variation, and improving efficiency at every step of the way. Whenever a water spider is implemented properly as part of manufacturing process it fits, it can boost productivity (for everyone else), while allowing the company to provide experience for future leaders.
Do you have a “water spider” position at your company? Do you call it “water spider” or something else? Add your comments below!