Analyzing the plastic soup problem with CRT

Analyzing the plastic soup problem with CRT

  • 16/09/2019
  • blog

The plastic soup is all over the news these days. News bulletins discuss the severity of the situation and show projects like the ocean clean-up project. Almost every day a study is published about how micro-plastics might affect our health.

This complex problem has many sides and factors. Therefore it is hard to understand the root problems, to have a real understanding of what is actually going on. In a case like that, it is always advisable to do some research and build a Current Reality Tree or CRT.

The theory of constraints

A CRT is a focusing procedure formulated by Eliyahu Goldratt, the developer of the theory of constraints. It is intended to help gain an understanding of causes and effects in a situation that needs a solution. A CRT treats multiple problems in a system as symptoms arising from one or a few perceived symptoms (along with secondary or hidden ones that lead up to these perceived symptoms). It lists undesired effects (UDE’s) and orders them in logical relationships to provide a clear view on causes and effects. This gives an insight in the core issues that need addressing.

A CRT-exercise on the plastic soup problem could look like this:

CREAX  plastic soup (CRT/Theory of constraints)

Plastic Soup CRT (for a bigger version of this CRT, see download option below this article). Root causes are shown in grey and causes or effects with a lot of impact on the parent problems are indicated with a green dot.



Identifying root causes

Once the CRT has been built we can identify root causes and UDE’s which have a huge impact on the underlying problems:

  • plastics remain in ocean,
  • known and unknown health issues caused by microplastics,
  • reduced biodiversity.

Note: The fact that plastics remain in the ocean has a negative re-enforcing effect on the other 2 problem statements.


Focus points to address

From this CRT we can derive multiple focus points to tackle the plastics soup:

Filtering waterways

1.  Capture plastics on waterways:

Most plastic ends up in the ocean via waterways. How can we catch these plastics before they end up in the ocean and deteriorate into smaller parts and eventually microplastics? Keep in mind that the solution should not hinder inland shipping.

Beter filteration installations

2.  Improve water filtering installations:

As it turns out water purification systems do not filter out all the plastics which enter through the sewage system. Apparently cotton swabs and many other types and sizes of plastic are not captured in these facilities. Off course some additional research would be needed and maybe a secondary CRT to get a grasp of how this could be done more efficiently in these facilities.

efficient waste collection

3.  More efficient waste collecting

In many countries, especially developing countries, waste collection is under par. There are not enough waste collection points (bins, containers) and even if the waste collection is sufficient, usually the waste processing is non-existent or inadequate. For instance, open landfills are very prone to winds picking up loose plastic and blowing them into waterways or the oceans. This is a huge factor in island-states.

multifunctional packaging

4.  Multiple use packaging

If single-use, non-biodegradable, packaging would have a secondary function, they would probably be discarded less. So can you think of an additional use for some packaging types? Bottles, bags, pouches, foils, trays, etc.

alternative packaging

5.  Alternatives for polluting products

The plastic soup mainly consists of single-use products like drinking straws, cotton swabs, bottles, plastic bags and can-rings together with discarded fishing nets. Therefore these polluting products need to be replaced with eco-friendly alternatives or disappear from our economy.

waste is money

6.  Waste is money

How to capture value from discarded plastics so that they do not get discarded? How to capture value from single-use plastics so they do not get discarded anyway.

What can we do with reclaimed plastic from:

  • littering
  • waterways
  • ocean surface
  • seabed

Keep in mind that the longer the plastics remain in the ocean, the more they detioriorate and the more they lose their value. Reclaimed plastic from the ocean is almost useless except for extracting energy through a pyrolysis process.

Sieving plastic from seabed

7.  Sieving methods for cleaning the ocean floor

This could very well be the most challenging problem. Albeit a very important one, since 70% of the plastics that end up in the ocean find their way to the seabed.

So how can we get all this plastic out of the seabed without damaging the eco-system?

new business models

8.  New business models for clean-up equipment/initiatives

Clean-up initiatives like the ocean-clean-up program are very expensive, so how can we sponsor such kinds of programs or further development of cleaning-equipment?

biodegradable packaging

9.  No durable plastic packaging (biodegradable, edible)

Plastic is too durable and not biodegradable, We need new types of plastic which can decompose quickly once discarded. These types of plastics will surely not be oil-based, but use plant-based materials.



The plastic soup problem can only be remedied if we tackle all of the above causes. It surely will take a lot of time and effort to do so, but knowing the problem is already half of the solution. If everyone contributes, even the smallest bit, and becomes aware of the problem and how to remedy it, then surely we can overcome this crisis.

Plastic Soup CRT

download a bigger version of the Plastic Soup CRT

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