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Workshop #2: Requirements

Design Brief

Design a way to make toast. Ensure a modular solution that can be expanded by end users such that the intervention is suitable for households of between 1 and 4 persons. Pay particular attention to the needs of disabled persons, and environmental concerns.

Workshop Assignment

Develop a PRS for this situation. A summary PSS is provided below for this workshop; use it as the basis for your team's PRS.

In particular, and following the design roadmap section for Project Initialization, your team must:

  1. create usage scenarios,
  2. develop requirements, and
  3. prepare a PRS.


This section provides a summary Strategy that would have been carried out for this project. It is not a complete PSS, but should contain all the necessary information you need for this workshop.

Situation Assessment

This is the result of a situation scan.

  • Middle-class (Canada) income
  • Singles: minimal / cramped / small apartments
  • Families: child safety, cleaning, durability
  • Capacity: 1-8 slices
  • Foods: sliced breads (Texas?), English muffins, bagels, hamburger buns
  • Location of intervention: kitchen(ette), conventional domestic NA power, sinks/faucets, counter space, reachability (interface)
  • Related locations: dining table, den, sitting room, bedroom
  • Cost: typical for middle-class


Helander [1] was used to find information about user abilities, dimensions, etc.

Searches of “ways to make toast” and “ways to cook toast” both on Google and Google Scholar yielded no useful results. The only clear sources of information involved “toasters.”

A Google search for “toaster” yielded the following exemplary products. We expect that Google results will be indicative of the most popular and modern currently available toasters.

HAMILTON BEACH Long Slot Keep Warm Toaster [2] \$54.99. One of the few toasters with a 2×2 configuration.
CUISINART 4-Slice Countdown Mechanical Toaster [3] \$119.99, on sale for \$101.99.
Sunbeam 2 Slice Extra-Wide Slot Toaster [4] \$17.98. Reviews of this toaster at [4] give it 4.4 / 5 stars.
T-Fal Avante Icon Toaster, 4-slice [5] \$149.99 on sale for \$74.99. Rated 3.2 / 5 stars at [5].

We compared prices of the same model of toaster at 2-3 different websites and found they were all within 5-10% of each other with discount stores like WallMart having slightly lower prices than other stores like Hudson’s Bay (excluding short-term “sales events,” where price differences were greater).

When searching for “toaster,” Google suggested other searches. “Toaster oven” was the only other search for a product class. However, we understood from the brief that the focus is on toast only rather than the more expansive function set of “toaster ovens.” We therefore limited research strictly to the making of toast, and not other uses of toaster ovens.

We also searched Google for “modular toaster.” Though there were many hits, all of them seemed to be “concepts” - i.e., not actual products on the market. Some exemplars include the following.

toaster5.jpg Modular Toaster [6]. Identical units that share one power connection.
toaster6.jpg Radical 6-Part Toaster [7]. Each element slides into a central core for support and power only. All other function is duplicated in each module. Source indicates no particular benefit to this arrangement.
toaster7.jpg The Optimist [8]. Intended to minimize waste during production and disposal. Designed for easy replacement of innards, and long-lasting exterior. NOT modular, but interesting with respect to sustainability.
toaster8.jpg The Pragmatist [9]. Multiple identical elements with separable power cord. Share power but duplicate all other function. Each element is small enough to fit in a UK mail slot to facilitate return to manufacturer for disposal. Materials carefully selected to ensure maximum recyclability.

A Google search for “innovative toasters” yielded many strange designs, none of which were currently feasible either because they were:

  1. radically different in form,
  2. failed to meet typical expectations (e.g., fit easily on a counter having upper cabinets directly above),
  3. lack of modularity, or
  4. obvious shortcomings for disabled persons.

The Wikipedia entry for toasters led us to a Consumer Report [10] which provided a list of features of different types of toasters. This list will be used to help guide Concept Design. Of the features listed, cleanliness and ease of operation were systemic to all toaster types. Modularity and universal usability were not listed at all.

Having searched for various “toaster technologies,” we found that resistance heating was the only technology used to make toast.

User Groups and Personas

  • End Users
    • Robert is 40 year old male owner of local pizzeria, married and father of 2 teenage children (one boy, one girl). His work allows him to stay at home in the mornings and make sure his children have a reasonable breakfast. He is of generally good health.
    • Adaline is a 72 year old widow who lives with her son, his wife, and their two teenage children. She is legally blind in one eye and needs a +3.00 reading prescription for her other eye. However, everyone thinks she acts much younger than her age suggests. She has been a housewife her whole life, and is used to cooking tasks. She is not, however, technically literate.
    • Agneta is an 8 year old girl of immigrant Danish parents. She is gifted, but her parents, who are factory workers, are not. She goes to school near her home. Her parents encourage her education, but often cannot keep up with her explanations and thoughts. She tries to help her parents, especially her mother, around the house, because her mother broke her right arm as a child and it was poorly set, resulting in general weakness in that arm.
  • Manufacturing
    • Stanislav is a 37 year old man who emigrated to Canada from Poland when he was 3 years old. He is subject to migraine headaches and slightly overweight.
    • Aulia is a 27 year old woman, born and raised in Saskatoon. She has moved to the Big City because she hopes to make a better life for herself. She is generally of good health, but of petite physical stature.
  • End of Life
    • Fred is a 26 year old, generally healthy and fit male who has started his own business recycling products. He owns a small shop that he has been converting into a disassembly “factory” for the last two years. He has a university degree in sustainability studies and a technologist’s certificate in metalworking and welding. His business model involves reclaiming discarded objects from recycling depots and garbage dumps, disassembling them, and reselling the metal to artists, DIY-ers, and when possible larger metal-working companies.

Reference Design

We chose the Cuisinart toaster [3] as our reference design for the following reasons:

  • It’s price was higher than average among the devices studied but not very expensive. While we wish to minimize cost, we recognize that introducing a new class of device due to modularity will likely induce higher costs. We assume a similar strategy as Tesla Cars: start with a rather expensive product to build the business; then, as we accumulate market share, expertise, and resources, introduce more economical products for a broader range of consumers.
  • Cuisinart has a good reputation and a long history in the sector, and is therefore probably a reliable standard for best practices.

Strategic Considerations

Market Segment

Middle-class blue- and white-collar families in North America, with emphasis on disabled individuals. Given our experiences with toasters and our review of available products, we believe vision, hand/wrist, and cognitive impairments will be most significant.

Degree of Innovation

Innovation focus is on energy conservation and ease of cleaning. Modularity and inclusivity were not listed as features of any type of toaster in [10]. This suggests an opportunity to establish a new product sub-class by simply addressing modularity and inclusivity.

Functional Complexity

All else being equal, keep complexity as low as possible; no bells and whistles. This will help lower complexity and cost, which will hopefully have knock-on effects on sustainability.

Time to Market

We believe 12 months to market is sufficient for design, test, and ramp-up, assuming sufficient corporate resources for all detailed design and life-cycle considerations are available.


Full production is 5,000 per year, with a possibility of increasing production if the product is a success.

Environmental Concerns and Maintainability

Ease of cleaning is very important, especially cleaning the inside of the device. The exterior should be easy to keep clean of sticky food particles that could rot, and easy to keep dry so mould doesn't form.


We were unable to determine what an appropriate level of profitability would be. However, we cannot sell the product at a loss. We will attempt to optimize for lower cost, constrained by other goals of functionality, usability, and durability.


It appears that some functional innovation will be needed to satisfy the design brief. As such, there is increased risk of the product failing in the market because it will be seen as “too different.” To offset this, focus groups and careful concept testing will be used to direct the design appropriately. Also, production ramp-up will be slower than usual, with special attention paid to warranty issues. This should help minimize economic risk to the company.


See Profitability.


The only aspect of customization arises from modularity in that users must be able to alter the number of food items that the device can toast at once. This will not be a frequent operation, possibly happening once or twice per year at most.

We conducted an informal survey of 15 family members and friends on this question. While all respondents believed customization would be a desirable feature for them, only 12 of 15 respondents indicated they would configure the toaster no more than once or twice during its usable lifetime.


  1. M. Helander. 2006. A Guide to Human Factors and Ergonomics (2/e). Taylor & Francis.
  2. WallMart. Sunbeam 2 Slice Extra-Wide Slot Toaster. Accessed 3 Oct 2015.
  3. Canadian Tire. T-Fal Avante Icon Toaster, 4-slice. Accessed 3 Oct 2015.
  4. Hadar Gorelik. Modular Toaster. Accessed 3 Oct 2015.
  5. Matt Gossington. Radical 6-Part Toaster. Accessed 3 Oct 2015.
  6. The Agency of Design. The Optimist. Accessed 3 Oct 2015.
  7. The Agency of Design. The Pragmatist. Accessed 3 Oct 2015.
  8. Consumer Reports. November 2012. Toaster Buying Guide. Accessed 3 Oct 2015.


One report per team describing the PRS as described in the design roadmap.

Your report will be graded according this rubric as well as this HF Matrix.

mec325/workshop_2_-_requirements.txt · Last modified: 2020.03.12 13:30 (external edit)