How to design a future proof system for a historic interface?

GE wall oven LCD interface design
Mar 2017 - Jan 2018
Project Overview
Designed a new wall oven user interface with LCD technology.
My Contributions
Led a team of 3 designers, started from conception to production in 10 month with 10+ design iterations and 8 rounds of usability tests. Worked closely with engineering and product management defining features and provide solutions under technical constraints, cost and timeline.
Teams Worked with
Cooking - Product Management
Electronic - Tech
Embedded Software - Tech
App - Tech
Consumer Insight - Research
Usability - Research
Industrial Design - Design
Crank Software - Dev Partner
PushStart - Consultancy

BACK
GROUND

History of the day: Vol. Oven Control

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Still Amazingly Easy To Operate?

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Why we want a LCD control in 2017,
10 years after 1st iPhone?

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Target users and their goals

Goals for 3 types of cooking

Manual

What:
Standard cooking methods such as Bake, Broil, Roast, etc. Need input of mode, temperature and time. Straight forward flow

Goals:
Bring familiar mobile devices experience to oven. Remove cluster and confusion by providing context and information just in time.

Challenges:
What is the best navigation?
Underwhelm hardware maybe slow

Algorithmic

What:
Algorithm controls heating power and time  suits best for selected food type. Need input of food type, doneness, thickness, etc.

Goals:
Create a intuitive menu structure for easy navigation. Define a template covers all  perimeters of algorithm  

Challenges:
Limited algorithms at launch.
QA of the algorithm and user trust

Connected

What:
Sync cooking settings easily from partner recipe providers. Users just need 1 click to start cooking.

Goal:
Smooth communication between apps and oven. Ability to save as favorite for future access.

Challenges:
How to navigate and manage recipes on oven?Limited efforts from partners

EXPLORE

Product road map

Knobs or no knob, that is a question

Process

Navigation and manual cooking

It's time to figure out the most suitable menu system, to satisfy all three kind of cooking. Couple ideas are thrown on the table, obvious winner included. The boss had an idea:

"Line" Concept

Exploring a signature UI control that could apply to various products with different technologies for better brand recognition.Used a segmented slider design to mimic controls on other products

"Picker" Concept

Focus on user familiarity, referring to similar UI components and gestures from smart devices’ UI. Menu navigation and parameter settings are achieved with a horizontal picker

A/B Test

All participants were requested to go through two tasks for each prototype, then complete SUS (System Usability Scale) and NPS (Net Promoter Score) survey items. Task 1 focused on Standard Cooking, including selecting mode, temp, cook time, and navigate back to previous screens. Task 2 focused on Gourmet Cooking, including navigating the food categories and set up different cooking parameters.


The “picker” style approach offered significant performance benefits (both improved speed and reduced errors) for temperature selection. There were no significant differences between the 2 for the gourmet task, although it trended toward the “line” prototype because all menu options were available on screen. Both designs scored very high on subjective measures of satisfaction scores (“suggesting delightfulness”) and the Net Promoter Score. --Human Factor Team

Reorganize the structure

Every detail, tested

Questions were raised about how user should input a time. 2 designs are prototyped for a new test. One is the traditional digi-pad design, which resembled the “primitive” method of input time since early 1900’s. The other design is much modern that uses a two digit picker as on smart devices.

Digi-pad

Good:
Conventional design
Huge affordance
Could be very efficient once learnt

Bad:
User wasn’t sure if they are typing minutes or hours
Causes edge case such as invalid inputs

Average First Attempt Time:

15s

Fastest Learnt Time:

5s

Picker

Good:
Familiar as mobile devices
Huge affordance
know how to use at first glance
Bad:
Will cause problem without good execution
Hard to stop at specific number
Not any faster even learnt

Average First Attempt Time:

13s

Fastest Learnt Time:

13s

Algorithmic Cooking

For the precision cooking piece, the first step was to gather information of internal existing resources, as well as external competitions. With every piece of information, we did a lot of card sorting to layout the  optimized information architecture, balancing the breadth and depth among different categories, and also considering the flexibility for future updates.

The precision cooking utilizes different cooking element in the oven(upper element, lower element and convection fan), paired with temperature probe, timer and heating profiles, to create the best cooking results for selected food type. Various food required different parameters, settings and flows, and a universal structure needed to be designed accommodating all the food items.

During this phase, we also explored the options for the visual style. The dark theme fit really well with the black mask on the control panel. Delicately crafted food photographs not only light up the UI, but also become the inspiration for our aspiring users. This happened to be a style named Chiaroscuro.

FINAL 
TEST

A new test was conducted with similar convection bake and precision steak work flow. We were testing against our previous-gen product, as well as competition products.  SUS (System Usability Scale) and NPS (Net Promoter Score) were measured for each product. The test result indicated our design is superior than competitions’ design from navigation, control and experience standpoint.

Would users approve?

THE END?

Our premium line, MONOGRAM, is have a luxury and professional style. The knob is one of the key element defining the professionalism. knob units vs non knob units, how to make the same UI work for both?

It's time to figure out the most suitable menu system, to satisfy all three kind of cooking. Couple ideas are thrown on the table, obvious winner included. The boss had an idea:

Misc.

More features are designed such as settings, commissioning (how to pair oven with mobile app), service mode(for service technician diagnosis), demo mode(for showroom floor) and measures for better connecting conversion.

The visuals

An issue we had was the contrast problem on the display we picked for the oven. It was not the best quality display but to my surprise, the supplier had no way to adjust the display contrast. The design team in the end had to over adjust the contrast of our UI and food photos to compensate the display, as you can see from the left image. Another display related problem was that , the pixels are not square. A perfect circle on computer will turn into oval on the oven. Adjustments had to be done in photoshop’s pixel aspect ratio feature.

The Motions

The Bugs

Future proof?

Lessons learnt

UX Design

Respect engineers, talk their language, use their tools

The design is never done when you sent the deliverable, designers need to get as much involvement as possible to ensure the implementation match the design intent, and to polish the final product to single pixel level.

Better solution for UX deliverable needed

The wireframes will grow bigger daily, until to a point that is impossible to navigate and keep track off. I was experimenting Github Wiki for better documentation.

Business

Always strive for better hardware

During the development, we couldn’t solve some of the hardware problems, especially about the display. Everyone in the business realized we need better display when it was all too late to specify and source new parts. It could be perfectly resolved if we ask a bit more or spend extra in the beginning.

All the stakeholder should meet together on fast moving projects

This method had been proved very efficient in making quick decisions. There will always be issues that not everybody is aware of. Let’s talk them over, make compromises and keep going.

Engage with partners as early as possible

Too much time was spent negotiating with partners, the business should engage potential collaborators early on or even on daily bases, so the design time could have better understanding and design better experience, rather than providing subpar solutions in the last minute.