By focusing on food waste, we can all contribute to improved soil, plant and planet health. Every year in Australia over five million tonnes of food ends up as landfill, with 35% of the contents of the average household bin being food waste.

This World Soil Day we chat with Dr Savindi Caldera, Research Fellow in the Cities Research Institute, about the application of lean and green thinking to turn food waste into a super dynamic compost. Dr Caldera also provides some tips on fighting food waste to ensure ‘Good for planet and people’ practices.

Tips to reduce food waste

  1. Reduce over purchasing—plan your meals and keep track of the food you are purchasing
  2. Separate food waste from general waste—make compost at home, provide to community gardens or contribute to collections in your apartment complex or neighbourhood
  3. Recycle carefully—contaminated recycling takes more time and resources to sort at the waste facility
  4. Increase your knowledge and awareness—food waste and recycling are simple concepts that have become unnecessarily complex
  5. Seek out recipes for using the leftovers in your fridge—try out these recipes
  6. Advocate for regulatory support—going forward it is a collaborative effort between compost waste companies and waste supplies
  7. Champion STEM (science, technology, engineering, and mathematics) education for children—this is where we will see the future unfold.
Photo of Dr Savindi Caldera looking at the camera and smiling

Dr Savindi Caldera


Q & A:

What is lean and green thinking and how did it lead you to develop the 3P (Planet, Profit, People) model?

Lean and green thinking focuses on ‘doing more with less’, becoming more resource efficient and reducing waste. This is an extension of lean thinking which primarily aims to eliminate non-value-adding activities. Before my PhD in Environmental Engineering (Lean and green thinking), I was working in the corporate sector as a sustainability specialist and noticed that whilst the company had a heavy focus on lean processes, they always looked at them separately despite the many synergies. For some reason this resonated with me but as a graduate I was unable to clearly articulate or demonstrate the benefits, so I made the decision to learn more. I wanted to explore how lean and green thinking could help to close the loop on food waste; how we could use compost to be leaner and greener.

The 3P Model resulted from my PhD research into how 13 small and medium-sized enterprises (SMEs) in South East Queensland could readily engage in lean and green processes to achieve sustainable business practices aligning with the ‘3Ps’—Planet, Profit and People. In Australia, SMEs make up more than 95% of businesses and due to scale, and to financial and expertise limitations, struggle with being sustainable. So, it was interesting to speak with Chief Executive Officers and senior managers involved in sustainability and lean manufacturing to see the actual barriers they were facing and to uncover different opportunities they could leverage going forward. They needed a strategy that would provide the carrot and the stick – achieving sustainable outcomes plus gain financial benefits. The Model is easy to follow and provides a four-step process for SMEs to engage in lean and green thinking. My research work on creating value from waste was presented in a Channel 7 news piece in December 2017.

I also received the QUT Siganto Foundation Medal for demonstrating excellence in engineering-related research.

Three people standing and smiling at the camera. Two of them are holding an award together.

Dr Savindi Caldera being presented the QUT Siganto Foundation Medal.


Why was Rocky Point such an interesting case study?

Although a small company, and one of the original 13 SMEs, Rocky Point had a vision of wanting to be a progressive and sustainable company, contributing to the United Nations Sustainable Development Goals. Through my PhD study, Rocky Point had identified lean and green strategies that could help them streamline manufacturing and, seeing the benefits, wanted to continue building on their connection with us.

After my PhD study, Rocky Point was awarded the tender for composting food waste from the 2018 Commonwealth Games, Gold Coast. Keen to share lessons learnt, in 2019 Rocky Point worked with the local city council to pilot projects for the management of food waste produced in the Gold Coast commercial sector—hotels, shopping centres, restaurants.

Rocky Point diversified their business from sugar cane mulch and fertiliser to producing dynamic products based on value-added food waste. Through trialling these value-add fertilisers, Rocky Point also gave us the ability to engage with end users and we were able to identify key benefits in using food-based waste fertiliser—rather than chemical fertiliser—as compost. End users claimed increased product yield, improved soil and plant health, and cost benefits. More research is needed, and I am keen to collaborate with soil experts, to create an evidence base to help people better understand and communicate the clear benefits of food-based compost.


What sparked your passion for the environment?

In his recent documentary, ‘David Attenborough: A Life on Our Planet’, Sir David expressed it perfectly when he used the nuclear explosion at Chernobyl to show that the environment can regenerate without us, but we cannot regenerate without the environment. At 21 years old I represented Sri Lanka, my country, at the Climate Change Championship Programme organised by the British Council and advocated for mitigating measures and reforestation projects. This gave me the passion to continue being a champion.

I also am passionate about empowering the next generation of Queensland environmental scientists and engineers, particularly engaging with female STEM students, and students who may be the first in their family to attend university, and who are succeeding in the face of significant family challenges.

As a sessional lecturer in the School of Engineering and Built Environment I love being able to share real world examples of lean manufacturing and lean thinking in my master’s course units. Master’s students already have industrial experience in Australia or overseas, so these students are going back to the workforce, they are the change makers. In my lectures I strive to expand their thinking and to instil messages around lean and green and around UN Sustainable Development Goal 12: Ensure sustainable consumption and production patterns.


What projects are you currently working on? 

I joined the Cities Research Institute in 2018 as a Research Fellow and am working with industrial stakeholders and partners on four different research projects which all revolve, in some aspect, around sustainability:

  • End markets for construction and demolition waste—collaboration with RMIT to research recycling demolition waste
  • Transit activated corridors—collaboration with Curtin University to look at how urban regeneration could take place and how we could create sustainable urban design through holistic thinking
  • Sustainable procurement methods—sustainable, fair and equitable procurement from local providers is especially relevant with COVID-19 impacting many industries
  • Aviation emission reduction working group—an implementation plan specifying options to achieve the target through consultation with the university community.


What advice would you give students? 

Find your passion, follow your dreams and see how you can contribute to making a difference in the world. By being an environmental scientist, I believe I can not only make a difference, but I also can help address 21st century problems with nature inspired, place-based solutions.

It does not matter what you study if you can turn good intentions into meaningful impact.


Who has inspired you?

It was through my representation of Sri Lanka at the British Council’s Climate Change Championship Programme that I saw Sir David Attenborough’s documentary on climate change. His dedication, encyclopaedic knowledge, passion and experience inspire me every day. If I could achieve a little fraction of what he has done I would be proud.

Seven people in hi-vis workwear standing around a pile of soil and looking at the camera while smiling and posing.


Read the research

Dr Caldera has published several research papers on lean and green thinking, and these are discoverable through Griffith Research Online:

Transforming manufacturing to be ‘good for planet and people’, through enabling lean and green thinking in small and medium-sized enterprises

Investigating the role of residual food waste recycling in closing the loop: Case study from the 2018 Commonwealth Games, Australia

Exploring the role of lean thinking in sustainable business practice: A systematic literature review

Evaluating the enablers and barriers for successful implementation of sustainable business practice in ‘lean’ SMEs

Exploring the characteristics of sustainable business practice in small and medium-sized enterprises: Experiences from the Australian manufacturing industry

Doing well by doing good: Sustainable manufacturing strategies and opportunities through ‘lean and green’ thinking

Applying a Place Making Sustainable Centres Framework to Transit Activated Corridors in Australian cities

Enablers and Barriers for Creating a Marketplace for Construction and Demolition Waste: A Systematic Literature Review

Read more Griffith research about soil management.


Media engagement

Watch media segments about Dr Caldera’s work on creating value from waste:

Channel 7 news piece on Commonwealth Food waste recycling project

Griffith University media release Commonwealth Food waste recycling project

Channel 7 news piece on application of lean and green thinking for mulch production

Sustainability Matters article on lean farming

CitySmart newsletter article on engaging STEM researchers in food waste composting research