# Dynamics NAV to Business Central On-Prem Upgrade Effort Calculator

> Source: https://netray.co/tools/dynamics-nav-to-business-central-code-upgrade-effort-calculator
> Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems.
> Section: Free Tools

## Short answer

Count your modified and new objects, set per-object hours, and see code, data, test and total effort for the NAV to BC14 to v25 to current upgrade path.

## Category

microsoft-dynamics

## Erp

Microsoft Dynamics NAV

## Audience

- NAV developer
- IT manager
- Business Central partner

## Tool

**Kind:** calculator

**Inputs:**

#### Modified standard tables

**Key:** modified_tables

**Type:** number

**Default:** 40

**Min:** 0

**Step:** 1

**Unit:** objects

#### New custom tables

**Key:** new_tables

**Type:** number

**Default:** 15

**Min:** 0

**Step:** 1

**Unit:** objects

#### Modified standard pages

**Key:** modified_pages

**Type:** number

**Default:** 60

**Min:** 0

**Step:** 1

**Unit:** objects

#### New custom pages

**Key:** new_pages

**Type:** number

**Default:** 25

**Min:** 0

**Step:** 1

**Unit:** objects

#### Modified standard codeunits

**Key:** modified_codeunits

**Type:** number

**Default:** 30

**Min:** 0

**Step:** 1

**Unit:** objects

#### New custom codeunits

**Key:** new_codeunits

**Type:** number

**Default:** 12

**Min:** 0

**Step:** 1

**Unit:** objects

#### Custom or modified reports (RDLC/Word layouts)

**Key:** reports_custom

**Type:** number

**Default:** 35

**Min:** 0

**Step:** 1

**Unit:** reports

#### XMLports and converted dataports

**Key:** dataports_xmlports

**Type:** number

**Default:** 8

**Min:** 0

**Step:** 1

**Unit:** objects

#### Hours per modified object

**Key:** hours_per_modified_object

**Type:** number

**Default:** 4

**Min:** 0

**Step:** 0.5

**Unit:** hours

**Help:** Rule of thumb: move the change into an event subscriber or table/page extension and retest

#### Hours per new object

**Key:** hours_per_new_object

**Type:** number

**Default:** 1.5

**Min:** 0

**Step:** 0.5

**Unit:** hours

**Help:** Txt2Al conversion and compile fixes for objects you own

#### Hours per report

**Key:** hours_per_report

**Type:** number

**Default:** 3

**Min:** 0

**Step:** 0.5

**Unit:** hours

#### Companies

**Key:** companies

**Type:** number

**Default:** 3

**Min:** 1

**Step:** 1

#### Data upgrade hours per company

**Key:** data_upgrade_hours_per_company

**Type:** number

**Default:** 16

**Min:** 0

**Step:** 1

**Unit:** hours

**Help:** Upgrade code, test runs and fixes for one company over a two-hop run

#### Testing effort

**Key:** test_pct

**Type:** slider

**Default:** 35

**Min:** 20

**Max:** 60

**Step:** 5

**Unit:** %

#### Starting point

**Key:** hop_count

**Type:** select

**Default:** 3

**Options:**

##### NAV 2015-2018: v14, v25, current (3 hops)

**Value:** 3

##### BC14 to BC24: v25, current (2 hops)

**Value:** 2

**Outputs:**

#### Objects and reports in scope

**Key:** objects_total

**Expr:** modified_tables + new_tables + modified_pages + new_pages + modified_codeunits + new_codeunits + reports_custom + dataports_xmlports

**Format:** integer

#### Code conversion hours

**Key:** code_hours

**Expr:** (modified_tables + modified_pages + modified_codeunits) * hours_per_modified_object + (new_tables + new_pages + new_codeunits) * hours_per_new_object + reports_custom * hours_per_report + dataports_xmlports * hours_per_modified_object

**Format:** hours

#### Data upgrade hours

**Key:** data_hours

**Expr:** companies * data_upgrade_hours_per_company * hop_count * 0.5

**Format:** hours

**Description:** Base hours cover a two-hop run; each extra hop adds half again

#### Testing hours

**Key:** test_hours

**Expr:** (code_hours + data_hours) * test_pct / 100

**Format:** hours

#### Total effort

**Key:** total_hours

**Expr:** code_hours + data_hours + test_hours

**Format:** hours

**Primary:** true

#### Duration at 35 hours per week (one person)

**Key:** total_weeks

**Expr:** total_hours / 35

**Format:** weeks

**Chart:**

#### Total hours vs hours per modified object

**Type:** line

**X:** hours_per_modified_object

**From:** 1

**To:** 10

**Steps:** 10

**Series:**

- total_hours

**Disclaimer:** Per-object hours are rules of thumb from partner practice, not Microsoft figures. Replace them with your own after converting a sample of objects.

## Content

**Intro:** This calculator estimates the effort to take a customised Dynamics NAV 2015 to 2018 system to Business Central on-premises, where C/AL modifications must become AL extensions and data must pass through BC14 and v25. Enter your object counts and per-object hours and read code, data, test and total hours.

**Sections:**

#### The upgrade path this models

**Body:** Microsoft's supported path from NAV 2015, 2016, 2017 or 2018 to current Business Central on-premises is indirect. You first do a technical upgrade to Business Central Spring 2019 (v14), the last version that runs C/AL. From there the application must be converted to AL: export objects as text, convert them with the Txt2Al tool, and move modifications to standard objects into extensions. Starting with 2025 release wave 1 (v26), v14 cannot upgrade directly to the latest release, so data goes v14 to 2024 release wave 2 (v25) to the target, for example v29. Each hop is a separate data upgrade run.

**Bullets:**

- NAV 2015-2018: v14, then v25, then current (3 hops)
- BC14 to BC24: v25, then current (2 hops)
- BC v25 and later: direct to current

#### How the formula works

**Body:** Code hours = (modified tables + pages + codeunits) x hours per modified object + (new tables + pages + codeunits) x hours per new object + reports x hours per report + XMLports x hours per modified object. Modified standard objects cost more because the change must be redesigned as an event subscriber, table extension or page extension; new objects mostly convert with Txt2Al and need compile fixes. Data hours = companies x hours per company x hops x 0.5, so the default per-company figure represents a two-hop run and a third hop adds half. Testing is a percentage of code plus data. Weeks assume one person at 35 hours.

#### Worked example

**Body:** With the defaults, 130 modified objects at 4 hours give 520 hours, 52 new objects at 1.5 hours give 78, 35 reports at 3 hours give 105 and 8 XMLports give 32, so code is 735 hours. Three companies at 16 hours over 3 hops give 72 data hours. Testing at 35 percent of 807 adds about 282, for a total near 1,089 hours, roughly 31 person-weeks. Move hours per modified object from 4 to 6 and the total rises by about 370 hours (138 objects x 2 hours plus 35 percent testing), which is why measuring a sample first matters.

#### Gotchas

**Body:** Object counts from the NAV object designer include objects you modified only slightly; filter by Modified and review version tags to count realistically. Code that edits standard posting codeunits is the most expensive to move, because it needs an event or a redesign. Dataports from older versions must already be XMLports by NAV 2013. Licence changes matter too: confirm your licence covers BC on-premises before you plan the timeline. Run at least one full test upgrade of the largest company to time the data hops.

**Cta:** If you want users to query NAV or the upgraded Business Central in plain English on your own servers during and after the move, we can set that up.

**Faq:**

#### Can I upgrade NAV 2016 directly to the latest Business Central?

**Answer:** No. Microsoft's upgrade paths require NAV 2016 to go to Business Central Spring 2019 (v14) first, then to 2024 release wave 2 (v25), then to the target release. The path also requires converting the application from C/AL to AL, which is where most of the effort sits.

#### How long does a NAV 2018 to Business Central upgrade take?

**Answer:** It depends mainly on how many standard objects were modified. A lightly customised system may take a few hundred hours; a heavily modified one can take well over a thousand. Use this calculator with your object counts, then convert a sample of objects to replace the default hours with your own.

#### What is Txt2Al?

**Answer:** Txt2Al is Microsoft's command-line converter that turns C/AL objects exported as text from the NAV or BC14 development environment into AL files. It handles syntax conversion; it does not turn modifications of standard objects into extensions, which a developer has to redesign.

#### What is the difference between Dynamics NAV and Business Central?

**Answer:** Business Central is the successor to NAV. From v15 it uses AL and extensions only, with no C/AL, and runs in the web client. It is available as Microsoft-hosted SaaS or on-premises. NAV versions use C/AL and the Windows client, and customisations change standard objects directly.

## Search terms

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