# ERP Implementation Effort Estimator: Consulting Days, Cost and Duration

> Source: https://netray.co/tools/erp-implementation-effort-days-estimator
> Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems.
> Section: Free Tools

## Short answer

Estimate consulting days, cost and calendar duration for a mid-market ERP rollout from modules, sites, integrations and the share of requirements needing customisation.

## Category

erp-migration

## Region

Europe

## Audience

- ERP project manager
- Implementation partner
- CIO

## Tool

**Kind:** calculator

**Currency:** EUR 

**Inputs:**

#### Modules in scope

**Key:** modules

**Type:** number

**Default:** 7

**Min:** 1

**Max:** 30

**Step:** 1

**Unit:** modules

**Help:** Finance, purchasing, sales, inventory, production planning, quality, service and so on.

#### Base days per module

**Key:** days_module

**Type:** number

**Default:** 22

**Min:** 5

**Max:** 80

**Step:** 1

**Unit:** days

**Help:** Configuration, workshops, test and documentation for a standard module.

#### Plants or legal entities

**Key:** sites

**Type:** number

**Default:** 2

**Min:** 1

**Max:** 20

**Step:** 1

**Unit:** sites

#### Requirements needing customisation

**Key:** custom_pct

**Type:** slider

**Default:** 15

**Min:** 0

**Max:** 60

**Step:** 1

**Unit:** %

**Help:** From your fit-gap result.

#### Integrations

**Key:** integrations

**Type:** number

**Default:** 5

**Min:** 0

**Max:** 40

**Step:** 1

**Unit:** interfaces

**Help:** EDI, CRM, webshop, MES, banking, e-invoicing, CAD/PLM.

#### Days per integration

**Key:** days_int

**Type:** number

**Default:** 14

**Min:** 3

**Max:** 60

**Step:** 1

**Unit:** days

#### Users to train

**Key:** users

**Type:** number

**Default:** 80

**Min:** 1

**Step:** 5

**Unit:** users

#### Consultants on the project

**Key:** team

**Type:** number

**Default:** 5

**Min:** 1

**Max:** 30

**Step:** 1

**Unit:** people

#### Blended day rate

**Key:** rate

**Type:** number

**Default:** 950

**Min:** 300

**Step:** 25

**Unit:** EUR

**Outputs:**

#### Core configuration days

**Key:** base

**Expr:** modules * days_module * (1 + 0.25 * (sites - 1))

**Format:** number

**Description:** Each additional site adds about 25 percent of rollout effort.

#### Customisation days

**Key:** custom_days

**Expr:** base * custom_pct / 100 * 2

**Format:** number

**Description:** Custom work costs roughly twice the effort of configuring the same requirement.

#### Integration days

**Key:** int_days

**Expr:** integrations * days_int

**Format:** number

#### Training and change days

**Key:** train_days

**Expr:** users * 0.25

**Format:** number

#### Project management days

**Key:** pm_days

**Expr:** (base + custom_days + int_days + train_days) * 0.15

**Format:** number

#### Total consulting days

**Key:** total_days

**Expr:** base + custom_days + int_days + train_days + pm_days

**Format:** number

**Primary:** true

#### Services cost

**Key:** cost

**Expr:** total_days * rate

**Format:** currency

**Primary:** true

#### Calendar duration

**Key:** months

**Expr:** total_days / (team * 16)

**Format:** months

**Description:** Assumes 16 billable days per consultant per month.

**Chart:**

#### Total consulting days vs customisation share

**Type:** line

**X:** custom_pct

**From:** 0

**To:** 60

**Steps:** 30

**Series:**

- total_days

**Disclaimer:** Rule-of-thumb model for early budgeting. Customer-specific scope, data quality and partner experience move real effort materially. Obtain a fixed-scope proposal before committing budget.

## Content

**Intro:** Before vendors present proposals you need your own view of how many consulting days a rollout takes. This estimator builds the number bottom-up from modules, sites, integrations, training and the customisation share, so you can challenge a quote that looks too thin or too thick.

**Sections:**

#### How to use it

**Body:** Start with the modules you intend to go live with in the first wave, not the whole product catalogue. Enter the percentage of requirements your fit-gap analysis says need customisation. Adjust the team size to see how calendar duration changes: more consultants shorten the timeline but rarely in a straight line because client key users are the real bottleneck.

**Bullets:**

- Use first-wave modules only
- Take the customisation share from a fit-gap, not a guess
- Count every integration, including bank and e-invoicing
- Keep client key user availability in mind

#### How the model works

**Body:** Core days equal modules times base days, scaled by 25 percent for each additional site to reflect local master data, tax and workshops. Customisation is priced at twice its configuration equivalent. Integrations and training are added linearly, then 15 percent project management is applied to the sum. Duration is total days divided by team size times 16 billable days per month.

#### Reading the output

**Body:** Compare total days with the partner proposal. A quote far below your estimate usually hides assumptions such as client-delivered data migration or limited testing. A quote far above often prices custom work generously. The chart shows how sensitive the programme is to customisation: every extra 10 points of customised requirements adds a visible block of effort.

#### Common mistakes

**Body:** Teams underestimate data migration and testing, assume key users are fully available, and treat integration as a one-off task rather than design, build, test and cutover. Another mistake is applying one day rate to all roles. If senior architects do much of the work, use a higher blended rate.

**Cta:** Netray can review a partner proposal against this kind of bottom-up estimate and flag where scope or testing looks thin.

**Faq:**

#### Is this specific to one ERP?

**Answer:** No. The structure suits abas, proALPHA, IFS, Exact, Priority, Visma and similar mid-market systems. Tune base days per module to the vendor's typical effort for your industry.

#### Why is customisation doubled?

**Answer:** Custom work needs specification, development, test, documentation and upgrade regression, while configuration needs only setup and test. Two times is a common planning factor, not a law.

#### Does it include data migration?

**Answer:** Partly, through the base module days. For heavy legacy data, use the data migration effort calculator and add its hours to the total.

#### Can I use it for a rollout to extra plants?

**Answer:** Yes. Enter only the modules being rolled out and set sites to the number of new entities. The template effort is usually lower, so reduce base days per module.

## Search terms

erp implementation effort estimator, erp consulting days calculator, erp implementation cost estimate, how long does erp implementation take, erp project estimation, erp implementation time calculator, erp man days estimate

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