IT Unit Economics: Beyond Showback to Real Cost Per Service

The Showback Problem

Internal IT shared services have a transparency problem. Business units consume IT services but have no clear understanding of what those services cost, how costs scale with consumption, or whether their spending generates proportional value.

Most IT organisations attempt to solve this with showback — periodic reports showing business units their consumption of IT resources. While showback is a step above complete opacity, it creates its own set of problems:

• Allocation, not economics — Showback distributes the IT budget across consumers, but doesn't reveal what any individual service costs to deliver
• Retrospective, not operational — Monthly or quarterly showback reports arrive too late to influence spending behaviour
• Volume-only attribution — Most models allocate by headcount, device count, or ticket volume — none of which correlate to actual cost drivers

The result: business units see their IT bill, but learn nothing about per-service economics. IT leadership can't answer whether adding 50 ERP users costs $5K or $50K monthly. And when budget pressure arrives, cuts are made based on total spend visibility rather than unit cost analysis.

What Is IT Unit Economics?

Unit economics is the practice of calculating the fully-loaded cost of delivering a specific IT service to a single unit of consumption. The “unit” varies by service: a user, a transaction, a device, a ticket resolution.

Here's what unit economics looks like for an internal ERP service supporting 400 users:

This is fundamentally different from showback. Showback would tell Finance their share of the IT budget is $200K. Unit economics tells them their ERP service costs $151.91 per user per month, with 36.9% driven by licensing.

With unit economics, conversations change:

• “Adding 50 users adds approximately $7,600/month to ERP costs”
• “Licensing is the primary cost driver, so renegotiating the SAP contract has the highest impact”
• “Support costs are $33.75/user, while the industry benchmark is $28/user for this complexity tier”

Why 58% Are Stuck in Excel

Per TSIA's research, 58% of IT organisations still manage cost allocation in spreadsheets. The remaining organisations use partial TBM tools (24%) or ITSM-integrated costing (18%). Why hasn't unit economics been widely adopted?

Reason 1: Multi-layer cost attribution is hard

Real unit economics requires attributing costs across infrastructure, licensing, labour, and management layers — each with different allocation logic. Infrastructure follows resource consumption. Licensing follows user counts. Labour follows ticket volumes and project allocation. Combining these into a single per-service unit cost is manually intensive.

Reason 2: The data lives in separate systems

Financial data in ERP. Capacity data in PSA or timesheets. Infrastructure costs in cloud billing. Service catalogue in ITSM. Building unit economics requires pulling from all these sources and matching at the service level. Most organisations don't have this mapping.

Reason 3: TBM tools are over-scoped

Technology Business Management (TBM) frameworks promise comprehensive IT financial transparency. In practice, full TBM implementations are 6-12 month projects requiring dedicated taxonomy mapping, data integration, and ongoing governance. Many mid-market IT organisations can't justify this investment for internal cost modelling.

Beyond Showback: The Three-Layer Unit Cost Model

Moving from showback to unit economics doesn't require a TBM-scale project. It requires a three-layer model that can be built incrementally.

Layer 1: Service Catalogue with Cost Attachment

Define your services and attach direct costs at the service level. Each service gets its own cost structure: infrastructure, licensing, dedicated labour. This is the foundation — you can't calculate unit costs without service-level cost totals.

Layer 2: Multi-Layer Cost Attribution

Add shared costs: management overhead, shared infrastructure, cross-service support teams. Use allocation keys that match the actual cost driver (not just headcount). Infrastructure by resource consumption. Support labour by ticket volume. Management by service complexity.

Layer 3: Unit Cost Calculation

Divide the fully-loaded service cost by the consumption unit: users, transactions, devices, cases. This produces the per-unit cost that enables real economic decisions.

What Changes When You Have Unit Economics

Conversation 1: Budget requests

Before (showback): “IT costs increased by 8% this quarter.”
After (unit economics): “ERP cost per user dropped 3% to $147/user due to scale efficiencies. Total spend increased 8% because we added 90 users. The per-user trend is favourable.”

Conversation 2: Vendor negotiations

Before: “Our SAP costs are $22K/month. Is that reasonable?”
After: “We're paying $56.00 per user for ERP licensing. TBM benchmarks show $42-48/user for similar complexity. We have a clear renegotiation target.”

Conversation 3: Make-vs-buy decisions

Before: “Should we outsource service desk? Vendors quote $X/month.”
After: “Our internal cost per ticket resolution is $47. Vendor quotes $38 per resolution. But our first-call resolution rate is 78% vs their guaranteed 65%. Factoring in escalation costs, internal is cheaper.”

How DigitalCore Supports Unit Economics

DigitalCore implements the three-layer model as connected data domains — not a separate TBM overlay.

FAQ

What is the difference between IT showback and unit economics?

Showback reports the total IT cost allocated to a business unit or department, typically based on headcount, device count, or budget proportion. Unit economics calculates the cost of delivering a specific service per unit of consumption (per user, per transaction, per ticket). Showback answers “what did you consume?” Unit economics answers “what does it cost?”

Do I need to implement TBM (Technology Business Management) first?

No. TBM provides a comprehensive taxonomy for IT cost management, but a full TBM implementation is a 6-12 month project. You can build practical unit economics starting with your top 5 services using the three-layer model (service catalogue, multi-layer attribution, and unit calculation) without adopting the full TBM framework.

What data do I need to calculate unit costs?

At minimum: service-level cost breakdown (infrastructure, licensing, labour), consumption volume per service (users, transactions, devices), and shared cost allocation methodology. Most IT organisations have this data across 3-4 systems, and the challenge is connecting it at the service level.

How do I handle shared costs in unit economics?

Use allocation keys that match the actual cost driver. Shared infrastructure by resource consumption metrics. Shared support by ticket volume or time allocation. Management overhead by service complexity weighting. Avoid defaulting to headcount allocation for everything, because it distorts unit costs for services with non-linear cost structures.

How long does it take to implement unit economics for IT?

A practical implementation for your top 5 services can be done in 4-6 weeks. This includes defining the service catalogue, mapping cost layers, building the attribution model, and calculating initial unit costs. Expanding to full portfolio coverage typically takes another 2-3 months.