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HOW TO USE AN ACTOR MAP // USE_CASE_01

USING AN ACTOR MAP
TO FIND SYSTEMIC BUFFERS

AuthorAUGUSTINE VON TRAPP
Published2026.09.04
DomainMARITIME
Seattle-Tacoma gateway actor map annotated with arrows marking where physical buffering stocks and flows sit: between waterfront labor and terminal operators, terminal operators and vessel movement, and terminal operators and inland haul
Buffer locations annotated on the Seattle-Tacoma gateway actor map // click to explore the live map

I recently built an actor map of the Seattle-Tacoma container gateway: the forty-some businesses, unions, and agencies that move a container, and who each of them answers to. This post is about one way to use it.

What are we doing?

Actor maps are great for those trying to understand the systemic character of any system, be it a port, a company, or any other ecology of relationships.

Once built, an actor map has perennial benefits, starting with the orientation the builder internalizes by making it and a topology you can use to locate systemic patterns.

Every system contains patterns that tend to emerge consistently among the relationships: stocks and flows, feedback loops, interfaces, orchestration layers, monitoring layers, reconciliation mechanisms, etc. Knowing where to look for the abstract allows you to find the concrete instance, and more importantly, understand the context in which it exists.

These patterns represent leverage points, which are points at which a system can be improved.

In this case, we are looking for buffers using the Seattle-Tacoma Gateway Actor Map.

Why buffers?

Buffers are important to the resilience and reliability of a system’s operation when faced with regular and unexpected variance. Finding them, improving them, or introducing them has high potential to improve the lives of the people within the system as well as improve the overall system itself.

The entire port ecosystem must absorb shocks and variability it does not control. Regular oscillations such as demand surges, regulatory change, and business cycles, as well as larger disruptions like political upheavals, natural disasters, and supply chain disruptions frequently cascade through a web of highly enmeshed relationships. If the system cannot absorb, dodge, or otherwise handle such variations and shocks, it will experience acute dysfunction, financial loss, and a deteriorating reputation.

Failure to handle variance is a clear economic reality, but it also represents a poignant lived experience: inadequate buffers cause stress, overworking, layoffs, and general human and organizational insecurity.

Buffers exist to handle these shocks. Some are obvious (e.g. container yards) and some are more nuanced (e.g. legal and financial instruments that protect the flow of goods from political and legal disruption).

Obviously, the ports have survived this long and faced global and regional disruptions throughout their early and recent history, so buffers are here somewhere. Our goal is to find them and make a few observations.

How to find them

First let’s lock down what we are looking for: A buffer is a systemic pattern that describes the capacity to accept varying levels of input or external conditions and sustain function and consistent output.

It has a classic incarnation: a bathtub with a single drain. The drain will issue water at the same rate even if you turn the water on and off, the faucet spits water out twice as fast as the drain drains (varying levels of input), or a bucket of water falls over into the tub (external conditions). The tub may overflow eventually, but while it can contain all inputs, the drain will remain consistent.

Hand-drawn sketch of a clawfoot bathtub: a faucet labeled adjust the input higher and lower, a bucket pouring in labeled can handle unexpected inputs, and a drain labeled output stays the same
The classic buffer: whatever the faucet and the bucket do, the drain stays the same

In the wild, they can be as simple as the bathtub or very abstract, but finding them remains fairly simple because they always achieve the same function, no matter how sophisticated they are. Also, they tend to emerge organically or by design at specific points in pretty much every system.

You can usually find them topologically:

You can also look for behavioral indicators such as:

Once you start seeing them, you will see them everywhere.

What I found

I found many buffers using the actor map; here are a few of the interesting ones:

some are pretty straightforward…

…some are more subtle (or at least harder to see using the map):

Puget Sound Pilots staff and pilots at a conference booth with a banner reading Protecting Puget Sound Since 1935
Puget Sound Pilots // photo: Puget Sound Pilots

Insights

In a system this large, there are a huge number of buffers and interesting things to understand. While we are just scratching the surface, here is what I found:

The container yard + truck queue

Trucks queued at a Seattle container terminal gate with stacked containers, cranes, and the downtown Seattle skyline behind
Trucks at a Seattle terminal gate // photo: Northwest Seaport Alliance

Continuous import customs bonds and cascading information layers

The chassis pool

Bare container chassis stacked several high in a pool yard, DCLI branding visible
Stacked chassis waiting in a pool // photo: DCLI
Hand-drawn sketch of the gateway flow: ship to container yard to gate to truck queue, with the chassis pool feeding the trucks, and the continuous import customs bond at the exit gate settling later with Customs and Border Protection
The found buffers: sketched out here working together.

A couple ending notes when it comes to improving/dissolving buffers within a system

Conclusion

So, we used the actor map to find buffers and make insights! We found a lot of interesting things and have acquainted ourselves with the deeper nature of the port system using a general process.

The next step would be to take these insights and consider what improvements can be made to help the systems grow stronger while making sure to keep the known pitfalls of creating buffers in mind.

Thanks for reading!

Are you involved in any of the elements described here? I would love to talk to you and publish any corrections you have.

Also, please reach out if you want to talk about the port system, have feedback for me, or simply want to talk with a fellow systems nerd.