Retainer or One-Off Project? Use Annual Change Volume to Pick Your Outsourcing Model

An operations lead at a 60-person manufacturer laid two quotes on the table: Vendor A, one-off project at NT$480,000 with a 3-month warranty; Vendor B, NT$65,000 per month locked for 12 months, NT$780,000 total. Finance instinctively picked A — NT$300,000 cheaper on paper. But over the past year that company filed 27 change requests: report columns, an extra approval gate, a new logistics API. Under model A, those 27 items become 27 quotes, 27 scheduling rounds, 27 spec re-alignments.

Four Myths Worth Breaking First

Myth 1: "Pay only for what you use" is cheaper. The cost of project-based work is not on the quote — it is in every restart: re-aligning specs, rebuilding environments, re-reading old code. That is 6–10 hours per restart producing zero features. Six restarts a year is 36–60 sunk hours, roughly NT$72,000–120,000.

Myth 2: Unused retainer hours are wasted money. A retainer buys reserved capacity and response time, not an hours bundle. Treating it as an hours ledger pushes the vendor to invent pointless changes at month-end. The correct unit of pricing is an SLA plus a monthly floor of hours.

Myth 3: Advisory has no deliverables. The deliverable is decisions and vetoes. Blocking one wrong platform choice or one unnecessary in-house build usually saves six figures.

Myth 4: Full outsourcing means losing control. Loss of control comes from accounts you do not own, no deliverables inventory, and no exit clause — not from the model. Put those three in the contract and full outsourcing stays controllable.

The Core Framework: Annual Change Volume (ACV) × Internal Technical Judgment

ACV (annual change hours) = annual number of requests × average hours per request + annual routine maintenance hours

For most SMEs, average hours per request land between 6 and 16, and routine maintenance (dependency updates, backup checks, monitoring) runs 4–10 hours per month. Compute ACV, then add the second axis — does anyone internally judge whether a technical proposal is sound — and you get four quadrants:

Grey-zone rule: if ACV falls between 150 and 250 hours, run a 3-month retainer trial before committing. If ACV is high but the annual budget is uncertain, use a base retainer plus overage tiers — not pure project pricing.

Three Companies, Three Different Answers

The first company would lose money on a retainer; what it actually lacks is decisions like whether to build its own membership system. The third is the opposite — it can make decisions but lacks stable delivery capacity.

Hidden Cost Inventory for Both Models

Hidden costs of project-based work

• Every restart: 6–10 hours each, six a year is roughly NT$72,000–120,000
• New engineer reading legacy code: 40–80 hours
• Spec round-trip waiting: 3–5 business days each, directly delaying launch
• Deferred upgrades: Laravel's official support policy provides only 18 months of bug fixes and 2 years of security fixes; catching up past that window costs 60–120 hours

Hidden costs of an in-house hire

• Statutory employer cost: pension contributions of no less than 6% of monthly wages, paid entirely by the employer (Bureau of Labor Insurance), plus labor and health insurance shares — about 14–17% on top of salary
• Recruiting: headhunter fee of 1.5–2 months of salary; self-sourced hires average 45–70 days of vacancy
• Usable hours: after leave and public holidays, roughly 1,640 hours a year (82% of a nominal 2,000)
• Tools and seats: Vercel Pro at US$20 per seat/month (official pricing), plus monitoring and CI, about NT$3,000–6,000 per person monthly
• Turnover handover: one engineer leaving typically stalls output for 1–3 months

Per the Ministry of Labor occupational wage survey, software developers average about NT$55,838 in monthly total earnings. Add the costs above and the true annual cost is roughly 15–16 times the headline monthly salary.

A 10-Dimension Scorecard for Evaluating a Partner

Score each 1–5, out of 50.

Below 30, do not sign. 31–40, negotiate and add clauses. 41 and above, proceed to contract.

What ScriptWalker Offers — and Who We Are Not For

We run all four models: one-off Project, Retainer (with an hours floor and SLA), Advisory (fixed monthly hours, judgment only), and Full Outsourcing. Grey-zone clients start with a 3-month trial before any annual commitment.

Please do not hire us if:

• You want the lowest price to finish a spec and have no maintenance plan
• You need 24/7 on-call IT support (we are not an MSP)
• You need daily on-site presence
• The project is primarily machinery, PLC, or production-line hardware integration
• You have not decided to proceed and only want a quote to pressure your current vendor

A 90-Day Playbook for Moving from Project to Retainer

• Weeks 0–2 | Asset audit: move domain, cloud, Git, payment, and third-party keys into the company name; produce a deliverables inventory.
• Weeks 3–4 | ACV baseline: pull every request from the past 12 months, tag hours per item, compute real ACV.
• Month 2 | Half-rate trial: run 4 weeks at 50% of the target retainer and measure response time and throughput.
• Month 3 | Lock the terms: set the hours floor, SLA, CR tiers, and exit clause from trial data.
• Day 90 | Review: if actual hours deviate from the ACV estimate by more than 30%, change the model rather than forcing an annual contract.

Decision Checklist

• ☐ I know how many requests we filed in the past 12 months
• ☐ I can total the hours behind those requests (ACV)
• ☐ Someone internal can judge whether a technical proposal is sound
• ☐ Domain, cloud, Git, and payment accounts are in the company name
• ☐ Our framework version is still inside its official support window
• ☐ I know the communication cost of every project restart
• ☐ Requests arrive continuously, not as one-offs
• ☐ Our required incident response time is a specific number of hours
• ☐ We have an annual budget ceiling, not case-by-case approvals
• ☐ We are willing to pay for reserved capacity, not just hours
• ☐ I know which deliverables to reclaim when switching vendors
• ☐ The contract states exit handover timeline and scope

Eight or more checked: a retainer is usually cheaper. Four or fewer: start with an advisory diagnostic.

FAQ

What is the shortest sensible retainer commitment?

Run 3 months first, then discuss 12. Any contract demanding a 24-month lock from day one should be met with a written termination clause and handover scope.

Can unused retainer hours roll over?

Yes, with a cap. A reasonable rule is a maximum of 2 months of rollover, capped at 100% of the monthly floor, so you never accumulate a balance neither side can schedule.

Can project and retainer models run in parallel?

Yes — and above 500 ACV hours they usually should. The retainer covers maintenance and small changes while major rebuilds run as separate projects, so big work never blocks daily requests.

Advisory produces no code, so what am I paying for?

Fixed monthly hours. The deliverables are platform evaluations, vendor proposal reviews, architecture decision records, and an explicit do-not-build list. For companies without an IT manager, it usually returns the most.

Next Step

Start by computing your ACV. Send us your request log from the past 12 months and take a free 30-minute consultation: we will calculate ACV on the call, map it to the four-quadrant matrix, and give you a recommended model and cost range — no commitment required.

• Email: [email protected]
• Phone: 0916-224-047
• LINE: @ufv9089p