Contract Forms
Labo-type & Ukeoi-type
The essence
Read by color ― Navy = Labo-type (flexible, process-based) / Vermilion = Ukeoi-type (fixed, outcome-based)
Labo-type Contract
Labo-gata ・ selling “effort”
You secure a dedicated team for a set period and pay for the man-hours and time invested. The vendor works with due professional care, but does not promise the completion of a specific deliverable.
- Payment
- By man-month / hours
- Duty
- Due care (diligent work)
- Completion duty
- None
- Spec changes
- Flexible
- Risk
- Leans to the client
Ukeoi-type Contract
Ukeoi-gata ・ selling the “deliverable”
The vendor commits to completing a predefined deliverable and delivering it. Payment is made against completion and handover; the price is typically fixed (lump sum).
- Payment
- Fixed price (deliverable-based)
- Duty
- Duty to complete
- Non-conformity liability
- Yes (defect warranty)
- Spec changes
- Needs a change order
- Risk
- Leans to the vendor
Side-by-side comparison
Each row is a real question you face when signing and running the contract.
| Aspect | Labo-typeQuasi-mandate | Ukeoi-typeContract for work |
|---|---|---|
| ObjectWhat is sold | Labor & effort — the team’s time and skills | A finished deliverable — the result itself |
| Completion duty | None — no obligation to produce a deliverable | Yes — paid only upon completion & delivery |
| PaymentHow it’s calculated | By man-month / hours. Stable monthly cost, easy to budget | Fixed price for the scope. Total known upfront |
| Non-conformity liabilityDefect warranty | None in principle (no deliverable is warranted) | Yes — repair, price reduction, or damages |
| Spec changesChanging requirements | Very flexible — suits agile & fluid requirements | Rigid — scope changes need a re-quote & change order |
| Best when | Long-term, requirements still fluid, keep team & know-how | Scope clear, spec fixed, want lump-sum & risk transfer |
| Client-side risk | Higher — pay for hours even if the outcome is uncertain; needs management | Lower — no deliverable, no payment; risk shifts to the vendor |
Two ways of working
Labo-type runs as an Agile (Scrum) iterative cycle; ukeoi-type follows a one-way waterfall flow.
Labo-type (quasi-mandate)
Agile / ScrumProduct Backlog
Sprint Planning
Design (basic & detailed)
Development · Daily Scrum
Sprint Review
Retrospective
Repeat next sprint
Back to the first step (agile iteration)
Repeats each sprint (1–4 weeks), delivering value continuously while adapting to change. Billed monthly by man-hours.
Ukeoi-type
WaterfallRequirements
Design (basic & detailed)
Implementation
Testing
Delivery & acceptance
Payment
Done
Delivered — the contract is complete
Phases run top-down in sequence; each starts after the previous completes. The contract closes on delivery of the defined deliverable.
Quasi-mandate has two sub-types
Clarified by the 2020 Civil Code reform — important when drafting payment terms.
Paid by proportion of work
Payment tracks the volume of work / time invested, regardless of the final result. This is the classic “labo-type,” calculated by man-month.
Paid on achieving the outcome
Payment is tied to achieving an agreed outcome, yet it carries no “completion duty” like ukeoi. It sits between the proportion type and ukeoi — easily confused, so state it clearly in the contract.
Which should you choose?
Choose by how clear the requirements are, and who should bear the risk.
Choose Labo-type (quasi-mandate)
when…- ✓Requirements aren’t fixed yet and evolve as you go (agile, R&D)
- ✓Long-term project where you want a stable team and retained know-how
- ✓The client also helps set priorities and runs a flexible backlog
- ✓Work volume is hard to estimate for a fixed price
- ✓You need to scale the team up or down by phase
Choose Ukeoi-type
when…- ✓Scope and spec are clear; a concrete deliverable can be fixed
- ✓You want the total cost upfront (fixed price); easy budget approval
- ✓You want to transfer completion risk to the vendor
- ✓One-off work with clear delivery milestones
- ✓You don’t need — or want — to manage the daily process
This page is an internal explainer and does not replace formal legal advice; actual terms follow the signed contract.
