Chen Zhang Design Portfolio


Redesign the service-booking mobile web app workflow for car owners 

Problem Definition & Assumptions 

YourMechanic is a platform for on-demand car fix and maintenance service. I assume the core target users for this product are two kinds:

  • Car owners
  • Mechanics

As for car owners, the user needs and product value prop are the followings: 

  • Little transparency for the services in repair shop
    • Price (unclear labor hours, part price fairness)
    • Car issues (car industry jargons, quality of the repair service)
  • Time-consuming experience in a repair shop
    • Time: Only workday (appointment only available typically 8 to 6, Monday to Saturday) 
    • Location: drive to the shop location and wait

As for mechanics, the user needs and product value prop are the followings: 

  • Flexibility  
    • Flexible working hours
    • Flexible working location
    • Flexible to work on their favorite car type and service 
  • Recognition
    • Salary 
    • Customer satisfaction and happiness from car owners

Target Users & User Needs

BUsiness & Monetization Strategy

YourMechanic makes money by taking a cut from: 

  • Car parts
  • Car repair sales 

Design Scope and Assumptions

Now we can narrow down the design scope and list a few design assumptions for this design exercise. 

Target Users

General car owners 

  • Anyone who has a car needs maintainence and repair
  • Does not have so much technical and professional car repair knowledge 

User Needs in the Context of Booking Appointment

Primary User Needs

What problems do I have with my car? I want to find similar descriptions for my current car problem. 

  • What possible solutions do I have for this problem? I need a clear explanation and next-step inspection. 
  • How much is the repair? How much for the parts and how much for the work hours?  

Secondary User Needs

  • How long will it take? Can we get the whole job done with one appointment or multiple appointments? 
  • Where should we meet? What kinds of requirement for the repair location, parking lot or driveway? 
  • Who is the mechanic I should choose from? Can I see previous rating and reviews from other customers? 
  • How should I pay? Should I pay for any deposits when booking an appointment? 

Device Platform

  • Desktop web app
  • Mobile web app
  • iOS native app
  • Android native app

User feedback for the current customer experience

I did some online search on customer reviews from Yelp, iTunes store and Google Play store for the user feedback and possible design improvements. Basically, I categories the user complains of the customer experience into the following buckets below: 

  • Mechanics reliability (being late, not showing up, out of contact and quality of the repair job)
  • Visibility for payment and credit card charge
  • Price and repair work hours
  • Basic UI bugs

Current User Feedback 

Negative user reviews from Yelp, iTunes and Google Play 

Quantitive feedback from product usage tracking

User Acquisition

First-time users for multiple device platforms
Conversion rates for successful appointment booking among first-time users  
Click-through-rate for multiple steps in the booking funnel

User Retention & Engagement

Daily Active Users (DAU) / Monthly active users 
Number of appointments booked in a week/month
Number of services booked in each appointment 
Conversion rates for successful appointment booking 
What are the top car repair services? 
What are the top device platforms for car owners to use? 
What are the top cities and areas for our business in the 700 US cities? 
Who are our top mechanics? 

Qualitative feedback from user testing


Refine & Design Detailed Wireframes


Current Workflow


Redesign Proposal



YourMechanic is essentially a platform for on-demand car repair services. The foundation of this products are two kinds of users – car owners and mechanics. YourMechanic provides value to both target users by using the digital platform to connect car owners with mechanics. 

Booking workflow

If we have refined enough details and launched the redesign, I would return to the assumptions mentioned in the initial section to verify and figure out some open questions in my design solution: 

  • Which device platform should we target first and why?
  • What is the button-click-rate for the entry points to the booking funnels in different contexts?  
  • What is the conversation rate for the booking funnels in different contexts? 
  • What are the Click-Through-Rate for different steps along the booking workflow? Which one has the highest drop-off rate? 
  • How can we improve the user engagement and retention after first appointment? Regular car maintenance notifications, friends referral, car insurance and warranty etc? 
  • Can this redesign scale to other OS platform to maintain design consistency? 

We should rely on real quantitive usage data and qualitative user testing feedback data to inform our design iteration, and also consider business strategy and technology feasibility at the same time to refine our design solution.  

Outside the scope of this design exercise

Based on the current user feedback I gathered online, the quality and reliability of the mechanic directly impact the car owners' experience. We should treat these mechanics as our employees to provide online and offline training and support to help them give better on-demand repair experience so that YouMechanic can get higher customer satisfactions.

We can also try introducing the Super Mechanic badge concept to recognize and promote the superstar contributors in the mechanics community. This can help both the super mechanic himself get more business, and encourage other mechanics to provide better services to car owners.