Quantifying the total cost of ownership by modelling product lifetime

Quantifying the total cost of ownership by modelling product lifetime

Manivannan, Rengarajan (TU Delft Industrial Design Engineering)

Faludi, Jeremy (mentor)
Bolanos Arriola, J. (graduation committee)

Delft University of Technology

Integrated Product Design

2022-11-24

Consumer products produced in contemporary times face the issue of deteriorating durability, repairability and service life compared to products of yesterday. This deterioration is part of a bigger issue called planned obsolescence. Due to a ‘need’ to buy new products regularly, there is rampant consumerism which has created a decrease in raw-materials and an increase in the products and materials entering the waste streams. Therefore, it is imperative that this “cradle-to-grave” model is stopped. The EU and various governments in the EU have proposed legislation to transition from today’s linear economy to a circular economy. As part of that, there is greater emphasis placed on a product’s repairability, durability and product lifespan.
Repair scorecards are used to evaluate products on those parameters. However, the current scorecards have abstract scores that are difficult to interpret. Therefore, this thesis proposes a quantitative tool that calculates the total cost of ownership (TCOO) and service life of a product by modelling product lifetimes using failure modes.
This thesis begins with performing a literature study of linear economy and planned obsolescence, current scorecards, and their limitations. Questionnaires and interviews were conducted to understand what consumers wanted from a repair scorecard. The results from these were used to design the label and website of the TCOO tool. A system was created to facilitate the TCOO Excel tool, label, and website.
The mathematical model to calculate the TCOO was built-in to an Excel tool, and sample data was used to iterate upon them. Sensitivity analysis was also conducted to test the Excel tool. User tests were conducted to test if the Excel tool was intuitive to use and the flow of the tool iterated upon. User tests were conducted to refine the design of the label and the website.
The main contribution of this thesis lies in presenting the factors of repairability, durability and product lifespan in terms of cost, modelling product lifetimes, and moving from a priority component-based calculation system to a failure mode-based system. Using this tool, consumers can make informed purchase decisions, and manufacturers get data regarding failure, and legislators get data to introduce new laws and mandates.

Cost of Ownership
Scorecard
Repairability

http://resolver.tudelft.nl/uuid:cd21c509-2dfc-43d6-bece-72df1ba723fb

Student theses

master thesis

© 2022 Rengarajan Manivannan