How to Choose a Startup Idea: Bring Your Own, Start From a Sector, or Answer an Open Call

By Kasper-Tanakrit Sermsuksan · Global Venture I: Playbook · Block A

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In short: There are three good ways to choose the problem your venture is built on. Route 1: your own startup idea — if you can show evidence that the problem is real and give it an honest readiness self-score. Route 2: no idea yet? Start from a sector you care about — at SEA Bridge, Food & Drink; Health, Wellness & Beauty; Education; Creative Economy, with Longevity across all four. Route 3: answer an open call that names a real problem, such as TLV's Call for Ventures. None is easier. Each one asks for evidence.

Try it in 10 minutes: Write your one-paragraph case in four sentences: who has the problem, how you know (name the evidence), why you, and why now. Then underline every phrase that is an opinion rather than evidence. If most of it is underlined, you have found your first job: go and talk to customers.

Here is the question I want you to stop asking: is my idea good enough?

Nobody can answer it. Not me, not your friends, not an investor.

Only customers can. And only with what they do, not what they say.

I learned that the cheap way. A head of growth at a unicorn once gave me $300 and one week to find 100 interested customers for a travel idea I was sure about. I found 34. That week told me to move on.¹ The full story is in MVP & Prototype.

That one week told me more than months inside my pitch deck.

So I never ask my students how good their idea is. I ask what evidence they have. Your first decision — where your venture comes from — works the same way.

What are the three routes?

• 1. Your own startup idea — Who it is for: You already have an idea you care about — and some proof the problem is real — What you start with: Your idea, early evidence, a readiness self-score, and a one-paragraph case
• 2. A SEA Bridge sector — Who it is for: You want to build, but you don't have an idea yet — What you start with: A sector: Food & Drink; Health, Wellness & Beauty; Education; or Creative Economy — with Longevity across all four
• 3. TLV's Call for Ventures — Who it is for: You want a clear, real problem to start from — What you start with: One of six challenges in Taste, Touch or Tone, from thailandlongevity.org

All three can lead to the same place: a validated venture concept. None is easier. The best route is the one you can back with evidence.

✦ If you are doing this as part of Global Venture I: Playbook

You choose one of these three routes for the venture your team builds all course. All three lead to a validated venture concept by the end of the course: same blocks, same forms, same grading. TLV is a suggested starting point, not compulsory.

Can I bring my own startup idea?

Yes. Your own idea is welcome. But I want it to be somewhat valid.

Not proven. Not perfect. Somewhat valid means three things:

1. Early evidence. Something outside your own head says the problem is real. A few conversations with people who have the problem. A sign-up page with real sign-ups. Notes from your own work where you saw the problem again and again. Not "my friends liked it".
2. An honest readiness self-score. Place your idea on the KTH Innovation Readiness Level, area by area. Evidence of a real problem sits around Customer readiness (CRL) 2. Most ideas at this stage score low on most areas. That is normal. What matters is that the score matches the evidence.
3. A one-paragraph case. Who has the problem, how you know, why you, and why now. If you cannot write it, you are not ready to build yet.

Here is the difference:

• "I want to build an app for students to find study partners. Everyone I asked said they would use it.": "Second-year engineering students struggle to find study partners for hard courses. I asked 9 classmates I did not know well; 7 described the same problem and 4 said they had dropped a study group because schedules never matched. 23 people joined a sign-up form in three days. readiness self-score: CRL 3, BRL 1, TMRL 2, FRL 1. I want to test whether they would pay, or whether the university would." [illustrative]

Why CRL 3? Nine conversations with people who have the problem are first direct feedback from the market — that is CRL 3 on the KTH scale ("received feedback from primary market research"). Desk research alone would be CRL 2 ("typically derived from secondary sources")². The weak case has neither: "everyone said they would use it" is an opinion, not evidence.

If you recognize your own idea in the weak case, don't worry. Many first drafts look like that. The fix is more conversations, not better wording.

✦ If you are doing this as part of Global Venture I: Playbook

There is no minimum IRL level for your own idea, but you need evidence of a real problem: about CRL 2. Write your one-paragraph case to the instructor in Form A+B. If I am not convinced, I will tell you why. You can strengthen the case, or start from a sector or TLV's Call for Ventures instead — and often bring the best part of your idea with you.

What if I don't have an idea yet?

Good. You are not behind.

In my experience, most founders do not start with an idea. They start with a problem they keep bumping into.

Route 2 gives you a field to look in. SEA Bridge works in four sectors, with Longevity running across all of them:

• Food & Drink — e.g., small food producers who cannot prove quality to export buyers [illustrative].
• Health, Wellness & Beauty — e.g., older adults who stop exercising after a fall scare [illustrative].
• Education — e.g., vocational students who cannot show employers what they can actually do [illustrative].
• Creative Economy — e.g., Thai designers and musicians who earn little from work people love abroad [illustrative].

Pick a sector you are curious about. Then let customer interviews turn that curiosity into a problem statement.

What is TLV's Call for Ventures?

Thailand Longevity Ventures (TLV) is SEA Bridge's hub for building longevity ventures from Thai heritage and modern Thai know-how. Its line is "Thai wisdom. Made scientific."³

TLV publishes a Call for Ventures — an open list of problems we want founders to solve, in the spirit of Y Combinator's Requests for Startups⁴. Selected ideas can move on to venture building with SEA Bridge and partners.

There are three tracks and six challenges⁵:

• Taste — Challenge: Thai Origins — What TLV asks: "Prove and grade Thai ingredients, so the world pays for quality." — Example venture [illustrative]: A grading and certification service for premium Thai honey or turmeric
• Thai Nourish — Challenge: "Make Thai food that tastes great and keeps blood sugar steady." — What TLV asks: Lower-sugar Thai desserts for people managing diabetes
• Touch — Challenge: Thai Care — What TLV asks: "Prove what Thai massage and spa do, so doctors and insurers can recommend them." — Example venture [illustrative]: A measured Thai massage program that hospitals and insurers can refer patients to
• Thai Move — Challenge: "Turn Thai ways to move, old and new, into programs that keep people strong and prevent falls." — What TLV asks: A Thai-movement coaching app for fall prevention in older adults
• Tone — Challenge: Thai Sound — What TLV asks: "Test whether Thai music can lower stress and blood pressure." — Example venture [illustrative]: Music and movement sessions for care homes, with before-and-after measures
• Thai Signals — Challenge: "Read voice, breath, snoring and hearing to catch health problems early." — What TLV asks: A screening tool that reads voice or snoring in Thai

I like starting from a call like this. The problem is already framed, so you can spend your energy on evidence instead of on guessing.

How do you choose a startup idea as a student?

1. Start with energy, not strategy. Which problem would you still want to think about in week six, when it gets hard?
2. Check the evidence you already have. If you have real evidence for your own idea, Route 1 is open to you. If you only have enthusiasm, start from Route 2 or 3.
3. Check your team. Who in your team knows the field, or knows someone who does? That is social capital — use it.
4. Check access. Can you reach five real customers for this problem — strangers to you — within three weeks? If not, choose a problem where you can.
5. Write your choice down, with one sentence on why.

I think step 4 matters most. A problem you cannot reach is a problem you cannot validate.

How do you commit to a challenge?

Write it down. I recommend five lines:

• Your route (1, 2 or 3) and, for Route 2 or 3, your sector or challenge.
• One sentence: who has the problem.
• Your riskiest assumption — the one thing that, if wrong, breaks the idea.
• Your baseline readiness self-score, area by area.
• For your own idea: your early evidence and your one-paragraph case.

Then show it to someone who will push back. If they push back, it is not a no. It is a question you need to answer with evidence.

✦ If you are doing this as part of Global Venture I: Playbook

Every route is confirmed in Form A+B, with the five lines above. I confirm it in the A+B debrief. If I push back, it is not a no. It is a question you need to answer with evidence.

Can I switch my challenge later?

Changing direction inside your challenge is expected. That is what evidence is for.

If your interviews show the real problem is somewhere else, follow it — and write down why.

Switching to a completely different challenge is a bigger move. I recommend doing it early, and only with the evidence that made you switch. After that, keep your challenge and change direction inside it.

✦ If you are doing this as part of Global Venture I: Playbook

You can switch to a completely different challenge until the end of Block C. Bring the evidence that made you switch, and write down why in your Venture update. After Block C, you keep your challenge and change direction inside it.

Reality check

Most people fall in love with their first idea. Then the first interviews break it.

That feels like failure. It is not. I moved on from my travel idea after 34 emails. The idea was wrong. The week was not wasted.

If you are struggling at this stage, you are like most people. It means you are doing the real work.

Frequently asked questions

What if I don't have a startup idea?
That is fine — most founders start with a problem, not an idea. Start from a sector you care about, or answer an open call such as TLV's Call for Ventures.

How do I know my startup idea is good enough?
You don't — and neither does anyone else, yet. What counts is evidence that the problem is real (about CRL 2), an honest readiness self-score that matches it, and a one-paragraph case that convinces someone who will push back.

Is there a minimum IRL level for my own idea?
No. You need evidence of a real problem, about CRL 2. The rest of your score just has to match your evidence.

Is TLV compulsory?
No. It is a suggested starting point.

Can my idea combine a sector and TLV?
Yes. Longevity runs across all four SEA Bridge sectors; a Food & Drink idea can also answer a Taste challenge.

Can I change my idea later?
Yes — changing direction based on evidence is the point. A full switch to a different challenge is easiest early, before you have built much on the first one.

Before you go — advice from the 2025 class. When I asked what the next cohort should know, one student wrote:

"Your first idea will be rejected, no matter how good it is. Just don't be so sad. Your idea is not 100% wrong. It just needs an adjustment."
— CEDT student, 2025 (lightly edited)

Thirty-four emails taught me the same thing.

✦ A Note for Global Venture I Students · Block A: Orientation & Mindset · Form A+B

Your challenge is not a test you pass once. It is the thing you will work on every block. Choose something you can stay curious about.

The rules in one place: one of three routes for the venture your team builds all course · own idea needs evidence of a real problem (about CRL 2; no other minimum level), an honest readiness self-score and a one-paragraph case that convinces the instructor in Form A+B · every route is confirmed in Form A+B · you can switch until the end of Block C · TLV is suggested, not compulsory. Guests, partners and feedback in the course often connect to TLV.

Do this before class:

1. Read TLV's Call for Ventures and the sector list. Shortlist two options.
2. In your Venture update (Form A+B), write your choice, who has the problem, and your riskiest assumption.
3. Give your idea a baseline readiness self-score. If you are taking Route 1, write your one-paragraph case.

Pre-class check (in Form A+B):

1. What are the three routes?
2. What three things make your own idea "somewhat valid"?
3. Name the three TLV tracks and one challenge in each.

Your progress: Customer readiness first — own-idea teams start with evidence of a real problem (about customer readiness 2); every team records a baseline on all six areas. How we measure progress

Skills you practice: Analytical thinking · curiosity and lifelong learning · spotting opportunities · valuing ideas.

Based on the KTH Innovation Readiness Level™ by KTH Innovation, licensed CC BY-NC-SA 4.0 (kthinnovationreadinesslevel.com).

Keep reading

• The Venture Log & Book Log — next in Block A: where your choice gets recorded
• The KTH Innovation Readiness Level: How We Use It (and What We Expect)
• MVP & Prototype — the $300 test, and how to test your riskiest assumption
• SEA Bridge: The Cross-Border Venture Studio for ASEAN Founders — the sectors and why

All articles in Block A · Orientation & Mindset

• A-01 The Story Behind SEA Bridge
• A-02 Can Entrepreneurship Be Taught?
• A-03 SEA Bridge: The Cross-Border Venture Studio
• A-04 Should You Start a Company?
• A-05 About Global Venture I: Playbook
• A-06 The Entrepreneur Interview
• A-07 Thank-You Letters
• A-08 The ASEAN Friend Interview
• A-09 How to Choose a Startup Idea (you are here)
• A-10 How to Keep a Startup Journal

References

1. Sermsuksan, K.-T. (2023). The Startup Mindset [in Thai], Chapter 4. Wish Publishing (สำนักพิมพ์วิช). English: the author's own translation, not yet published.
2. KTH Innovation. (n.d.). KTH Innovation Readiness Level™ [level descriptions]. Copy hosted by Fonds de recherche du Québec: https://frq.gouv.qc.ca/app/uploads/2025/02/kth-innovation-readiness-level_compiled_va.pdf — accessed Nov 2026.
3. Thailand Longevity Ventures. (n.d.). Thai wisdom. Made scientific. [Home page]. https://thailandlongevity.org — accessed Nov 2026.
4. Y Combinator. (n.d.). Requests for startups. https://www.ycombinator.com/rfs — accessed Nov 2026.
5. Thailand Longevity Ventures. (n.d.). The Challenge: Longevity Hackathon and Open Call. https://thailandlongevity.org/challenge — accessed Nov 2026.

About the author: Kasper-Tanakrit Sermsuksan is the Founder of SEA Bridge and a Visiting Lecturer in Computer Engineering and Digital Technology at Chulalongkorn University's Faculty of Engineering. Learn more →