ERP cost: build a total-cost model

Use one scope for every quote

List entities, sites, users, modules and integrations before collecting prices. Distinguish full users, shop-floor users and external access. Ask each vendor to map its quote to the same scope, with tax, currency and renewal assumptions visible. A low subscription figure tells little when a required production function is excluded.

Separate one-time and recurring costs

One-time costs can include configuration, migration, integration, testing and training. Recurring costs can include licenses, hosting, support, add-ons, AI usage and maintenance. Model internal project time separately. If an integration is described as standard, ask whether setup, monitoring and upgrades are included.

Model change and exit

Add a scenario for another site, more users and a major workflow change. Request renewal terms and any minimum commitments. Include data extraction, attachment export and transition assistance in the exit scenario. Document uncertainty as a range rather than replacing unknown items with zero.

Use the calculator as a worksheet

Our calculator adds your own assumptions over a chosen period; it is not a vendor price estimate. Enter comparable quotes, then compare a base and a downside scenario. Take the model to finance with the implementation schedule, resource plan and benefits owner. Savings forecasts should have a measurable baseline and a method to avoid counting the same benefit twice.

Build a quantity model before a money model

Begin with counts that operations can defend: people who post transactions, concurrent shop-floor stations, warehouses, legal entities, test environments, integration messages and retained attachments. Map each quantity to the vendor's actual charging unit. A device license and a named user are not interchangeable assumptions. Record how occasional approvers, contractors and seasonal staff are handled. Keep a separate row for features whose licensing is unresolved. The aim is to expose the multiplication behind a quote. If two suppliers price different units, translate both into the same operating scenario rather than comparing a user rate in isolation. Ask for a written reconciliation from these quantities to the quoted bill of materials.

Use a worked example without pretending it is a market price

Illustrative example: assume 60 units of initial external delivery work, 18 units of internal project effort and 12 units of recurring annual cost. A five-year undiscounted commitment is 138 units: 60 plus 18 plus five times 12. These are fictional accounting units, not currency or vendor pricing. A six-month delay might add another six recurring units if subscriptions begin before launch, plus the cost of running both systems. Make start dates explicit. If finance uses discounted cash flow, apply its approved discount rate consistently to both alternatives and preserve the undiscounted cash schedule. Do not hide implementation overruns inside a larger contingency that nobody owns.

Separate cash, staff capacity and accounting treatment

Internal employees may be paid under either option, yet their project time still limits capacity elsewhere. Show cash outlays separately from internal effort so finance can see both. Estimate hours by activity and role: data cleansing, testing, training attendance, process decisions and post-launch administration. Ask managers whether the time is actually available during inventory counts and financial close. Do not automatically count every saved hour as reduced payroll. State whether a benefit is released capacity, avoided hiring, lower external spend or a cash saving. Accounting treatment of expenditure belongs with your finance advisers; the buying model should retain enough detail for them to make that assessment.

Turn uncertainty into scenarios with triggers

Use a base scope, a realistic expansion and a stressed implementation. Change causal inputs rather than increasing every row by an arbitrary percentage. For example, adding a second plant may require another migration, local training and scanner configuration while reusing the chart of accounts. A delayed integration may require temporary manual reconciliation and additional test cycles. For each uncertain line, record an owner, lower and upper estimate, evidence date and trigger for revision. Ask whether optional work is a fixed deliverable, a capped effort or an uncapped time-and-materials obligation. A range makes uncertainty visible; an unsupported precise total merely disguises it.

Model maintenance of the useful configuration

Include the work required to keep reports, extensions and interfaces usable after change. Ask who tests an update against the critical order flow and who repairs a broken partner connector. Count nonproduction environments, test data preparation and monitoring where they are necessary. Business Central's documentation distinguishes entitlements from permission sets, illustrating why access scope and commercial entitlement should be checked separately. That documentation is not a price list. For every shortlisted product, obtain the current commercial terms for the named edition. A proposed feature may be technically configurable while still requiring another license, and a licensed feature may still need substantial delivery work.

Tie benefits to a baseline and an owner

Choose a few measurable outcomes such as fewer late material expedites, less manual invoice entry or shorter close preparation. Record the present volume, cost basis and measurement method before launch. If lower inventory and fewer shortages come from the same planning improvement, explain the relationship instead of counting every forecast at full value. Identify the process change and accountable manager behind each benefit. Review whether the improvement depends on training, supplier behavior or data cleanup that is outside the software scope. The purchasing pack should contain a cash schedule, capacity plan, assumption register and benefits ledger. Together these let a reviewer understand why one option is affordable and what must happen for its business case to hold.

Common questions

Continue your research

The following profiles provide a starting point for checking vendor-described scope. Inclusion is not a ranking or a statement that every requirement is supported.