Guide to Design Reviews

Author

Sidharth Babu : Team Captain from Summer 2023 - Summer 2024

Additions by Jacob Yan : Chief Engineer from Summer 2023 - Summer 2024

Background / Context

In the Spring of 2024, I decided to reinstate the tradition of doing formal design reviews as part of Solar's workflow. Prior to this, the most recent wave of formalized design reviews was back in the Fall of 2020, and as such, had fallen out of common practice. Furthermore, due to us not doing them, we also lost the knowledge on how to do them.

In pursuit of re-establishing this part of the design process, I decided that all of our electrical systems would do an SRR, PDR, MDR (Optional), CDR, and FDP.  The reason I only asked our electrical system was because our mechanical system was still working on finishing the previous-generation vehicle, had not yet begun next-generation design, and would not begin until Fall 2024.

Below, I have documented everything that I have established for the five major checkpoints, what I learned, as well as my template email for inviting outside reviewers. Note that I was not able to implement all of the components I have detailed for each of these reviews, and as such, some are simply suggestions.

One very important thing to note. Solar has always been a bit more akin to a "research lab", at least, while I've been on the team. We have a penchant for pursuing moonshot projects that are extremely innovative, but are not short-term projects. To that end, our design reviews may look a little different than other teams, who primarily focus on pure vehicle development.

Finally, its important to note that mechanical systems have a different design process than electrical systems so I have included a different set of design reviews and guidelines below.

Inviting alumni:

I suggest you try to invite alumni as much as you can. They will be the most supportive and most knowledgeable about solar outside of any current member or lead. I was not able to invite any to SRR due to planning errors, but I did invite them to the 2024 electrical PDR. 

Template Email

Hello all,

I hope this email finds you all well. Solar is thriving and growing, and as part of this year's cycle, we are hosting a XXXXX on XXXXXX.  Without you, the team would not be where it is today. I would love the opportunity for our current team to meet you all, and I know they will greatly value your insight and experience. 

For those able to meet in person, we will meet in a classroom in the ETC (204 E Dean Keeton St). There is free street parking on Dean Keeton St, San Jacinto St., or on 27th street (behind the Aerospace building). Please contact me at (XXX) XXX-XXXX when you arrive, and I will be able to let you in and provide you with the exact room number. We will provide refreshments and snacks.

Alternatively, if you would like to join in virtually, I will open a Zoom room at XXXXXX before the meeting.

The schedule for our event is as follows:

DOTW, MONTH DAY

System 1 - Start Time : End Time

  • System 1 Description

System 2 - Start Time : End Time

  • System 2 Description

....


Thank you for your time, and please let me know as soon as possible which, if any, systems you are available to attend the review for. I look forward to hearing from you!

Warm regards,

--
INVITER

DEGREE | Class of XXXX

The University of Texas at Austin
POSITION | Longhorn Racing Solar
Cell: (XXX) XXX-XXXX
Email: XXXX@utexas.edu

Inviting external reviewers:

I suggest you exercise discretion when inviting outside reviewers, as it is entirely possible that at some points, their presence is not beneficial. This could be due to a variety of reasons, I personally did not invite many to SRR due to a relatively hasty planning cycle, as well as a general discomfort with reviews across the team. I wanted to get them situated with the concept of presenting to an audience first. However, this may be different for later cycles.

Template Email (Adjusted from template provided by Kevin Yu, LHRE Chief Engineer for 2023-2024 Cycle)


Hello! My name is XXXX and I am the XXXXX of the Longhorn Racing Solar team here at UT Austin. We build a custom, solar-powered, race vehicle entirely from scratch, and are a purely student-run engineering team. We are hosting our XXXXX (long-form name of design review) for XXXX (year).

We would greatly value your presence at our event, as we believe your expertise would provide valuable perspective, and grant us valuable insight with which to improve our designs, and ultimately, our final product. Insert some filler specific to the person to fluff this section up.

We will meet in a classroom in the ETC (204 E Dean Keeton St). There is free street parking on Dean Keeton St, San Jacinto St., or on 27th street (behind the Aerospace building). Please contact me at (XXX) XXX-XXXX when you arrive, and I will be able to let you in and provide you with the exact room number. We will provide refreshments and snacks.

Alternatively, if you would like to join in virtually, we will open a Zoom room at XXXXXX before the meeting.

The schedule for our event is as follows:

DOTW, MONTH DAY

System 1 - Start Time : End Time

  • System 1 Description

System 2 - Start Time : End Time

  • System 2 Description

....


Thank you for your time, and please let me know as soon as possible which, if any, systems you are available to attend the review for. I look forward to hearing from you!

Warm regards,

--
INVITER

DEGREE | Class of XXXX

The University of Texas at Austin
POSITION | Longhorn Racing Solar
Cell: (XXX) XXX-XXXX
Email: XXXX@utexas.edu


Outline of each review (Electrical):

SRR: System Requirements Review

  • What problems are we solving?
  • What is our minimum viable product for this current vehicle? 
  • What are some problems / long-term projects that we think will help us solve problems better in the future?
    • This part will be covered greater in detail in PDR.
  • Should be roughly 45 minutes in length

PDR: Preliminary Design Review

Vehicle cycle specific items:

  • How are we solving the problems we outlined in SRR?  
  • Why are we taking that approach?
  • Designs and decision matrices for MVP / critical vehicle features. Emphasis on the justification. Tell me why your approach is best

Long term projects

  • Justification on why these projects should be pursued (highlight their innovativeness)
  • Initial predictions on timelines
  • Initial findings

MDR: Midpoint Design Review

  • This one may be optional / conducted on a system by system basis
  • How have designs progressed?
  • Have cost calculations updated / changed?
  • Have risks changed?
  • Are there changes in direction and why?

CDR: Critical Design Review

  • Presentation of final design
  • Justification of final design including testing / validation results
  • Explanation of testing philosophy and measures taken
  • Highlight any areas of concern 
  • Final manufacturing and delivery timeline
  • Final deliverable outline 

FDP: Final Deliverable Presentation

  • Presentation of final deliverable
  • Presentation of "user guide"
  • Locked and tagged release of all files necessary to recreate system from scratch (both hardware and software)

Outline of each review (Mechanical):

SRR: System Requirements Review (Entire Mechanical System)

  • What problems are we solving?
  • What are our high level goals for our system?
  • What is our minimum viable product for this current vehicle? 
  • What are our primary performance metrics we want to hit for this car?
  • Length of meeting dependent on system scope
  • The result of this review is to get everyone on the team in agreement with the overall design goals for the system that will inform brainstorming efforts

CoDR: Conceptual Design Review (System Level)

  • Leading options from all brainstorming efforts for overall structure of systems
  • List of secondary projects important to car development
  • Back of the envelope calculations to evaluate feasibility
  • Evaluation of costs/benefits of each system structure option with respect to design, interactions with other systems, and manufacturing
  • Evaluation of dev effort and potential benefit of each secondary project
  • Ranking of all possible choices for system structure given the analysis done
  • Ranking of secondary projects based on which should be finished first
  • Try to be as expansive as possible in all of your possibilities for brainstorming. If there are structures that you chose not to pursue, make sure to mention them as even bad ideas can have good concepts that can be implemented elsewhere. Be ready to mix your ideas by taking the best aspects from each
  • There should be a lot of discussion for this review as its important for deciding the direction that everyone's effort goes towards. I would allocate minimum the same time for discussion as for the presentation itself
  • Most secondary projects will be either self led enough or minor in scope enough that they don't require a future review and can just be internally reviewed, but if there is a project large/important enough don't hesitate to discuss it in the future
  • The result of this review should be a choice of direction for an overall design and which secondary projects should be pursued. However, non-favored designs should be kept in reserve in case the primary choice presents difficulty in actual implementation

PDR: Preliminary Design Review (System and Part level)

Vehicle cycle specific items:

  • Each component should have a PDR which can be internal and informal followed by a full system PDR which is a compilation of the component PDRs in combination with overall system performance characteristics
  • Full implementation in CAD, overview
  • Discussion of how the design holds up to design goals/metrics
  • Discussion of any unforeseen issues
  • Preliminary manufacturing plan
  • The result of this review should be a set of feedback to refine the direction of development or a plan to change system architecture if there are any fundamental issues

Secondary projects

  • Optional depending on scope/importance of secondary projects
  • Discussion of initial results/issues
  • Updates on scope/cost/need for the project

MDR: Midpoint Design Review (System and Part level)

  • This one may be optional / conducted on a system by system basis
  • Each component should have a MDR which can be internal and informal followed by a full system MDR which is a compilation of the component MDRs in combination with overall system performance characteristics
  • How have designs progressed?
  • Have cost calculations updated / changed?
  • Are there changes in direction that need to be discussed and why?
  • The result of this review should be a set of feedback to refine the direction of development

CDR: Critical Design Review (System and Part level)

  • Each component should have a CDR which can be internal and informal followed by a full system CDR which is a compilation of the component CDRs in combination with overall system performance characteristics
  • Presentation of final design
  • Reiteration of performance metrics
  • Full Manufacturing plan/methods and cost breakdown
  • Highlight any areas of concern 
  • Final manufacturing and delivery timeline
  • Final deliverable outline 
  • The result of this review should be a final confirmation of end of design or a quick set of actionable fixes