Where SI/SM Boundaries Break Down
Talk to growth-stage startups today and you'll hear the same complaint: "the spec we locked down last month has already changed again this month." Teams are building new modules while simultaneously fielding an endless stream of bug fixes and feature requests for systems already in production. Marketing wants landing page changes for a promotion, sales wants new customer data fields, and the CEO wants an MVP to validate the next idea.
The problem is that none of this moves fast enough under the traditional SI (project-based system integration) plus SM (separately contracted maintenance) model. SI typically takes two weeks to a month just to finalize requirements, get a quote, sign a contract, and kick off — and because scope is locked into the contract, any mid-project change triggers a formal change request process. SM, meanwhile, exists to keep an already-built system stable, not to build new features. Companies with fast-changing requirements end up either re-signing SI contracts repeatedly or requesting separate quotes every time a request falls outside the SM scope.
According to KOSA's (Korea Software Industry Association) 2026 average wage data, application software engineers cost around ₩7.75M per month in labor rates alone. Add SI project management overhead, deliverable documentation, and re-bidding administration, and organizations with frequently changing requirements end up paying a disproportionate share of their budget on process rather than actual development.
What Subscription Development Solves
Subscription development fixes this by changing the contract structure itself. Two things make the difference.
First, a single team handles both build and operations under one monthly contract, without interruption. When SI and SM teams are separate, every new release requires handoff documentation and a ramp-up period for the new team to understand the codebase. With subscription development, the same team owns the project from day one, so that overhead disappears.
Second, requirement changes take effect without contract renewal or re-bidding. Within a fixed monthly development capacity, only priorities need to shift — a feature decided this week can ship in next week's sprint. One POLYGLOTSOFT Standard-plan client, an e-commerce startup, added promotional pages, revised checkout logic, and built an admin analytics dashboard over three months — all under a single monthly subscription, with no separate contracts.
Cost and Speed Comparison: SI vs. SM vs. Subscription
| | SI (Project-based) | SM (Maintenance) | Subscription Development |
|---|---|---|---|
| Contract type | Per-project, fixed scope | Separate contract, maintenance only | Monthly, flexible scope |
| Average time to start | 2 weeks–1 month (quote/contract) | Separate contract after SI completes | Same day–3 days (after PRD) |
| Handling requirement changes | Rewrite change request, new quote | Separate negotiation if out of scope | Applied next month or immediately |
| Total cost of ownership | ₩50M–80M upfront + separate maintenance | ₩1M–3M/month | ₩290K–2.39M/month (build + operations included) |
*(Cost examples based on landing page to e-commerce MVP scale projects)*
Which Model Fits Your Company
Three questions help you self-diagnose:
If two or more of these apply, it's worth seriously considering a switch to subscription development.
How POLYGLOTSOFT's Subscription Development Works
POLYGLOTSOFT offers four subscription tiers based on page count and complexity, from Basic (₩290K/month) to Team (₩2.39M/month). Onboarding starts with a six-step PRD wizard — category selection, project overview, domain requirements, service environment (12 items covering platform, authentication, real-time features, external integrations, and more), design and timeline, and final review. Once requirements are defined, the development team starts immediately. When requirements change afterward, no new contract is needed — the same team, under the same subscription, simply reprioritizes. Once a project stabilizes, it can transition smoothly into an SM plan for ongoing operations. If your organization's requirements keep changing, the first step is simple: start filling out the project overview on the PRD page.