Your current solution will define your upgrade path to Business Central Online. Such is the nature of online services that in most cases, it becomes more a case of migration rather than upgradation.
The very first step to do generally is to import existing data in a Business Central online tenant through an empty company, during which the following scenarios might arise that you must know how to come out of:
D365 Upgrade from Dynamics NAV
Business Central has retired Codeunit 1 Application Management that was there in Dynamics NAV. It has replaced this with new ‘system’ codeunits in the 2 billion range. Also, it no longer supports V1 extensions for on-premises installations. Thus, all custom V1 extensions must be converted into V2 extensions in the old environment before embarking on the upgrade to Business Central online. Business Central no longer uses MenuSuite to control a page or report that can be found in the search feature of a Web Client. Rather, specific properties on the page and report objects control this. In case you plan to integrate Business Central with Dynamics 365 Sales, then a technical upgrade of the same will not suffice. It will have to be a full-scale upgrade to Business Central. Additionally, the Dynamics 365 Business Central 2019 version (latest release) has new and changed application features for users, administrators & developers. Moreover, to take full advantage of these features, end users must again do an application code upgrade and not just a technical upgrade.
Setting up a questionnaire-based company
When you perform a D365 upgrade to Business Central online, there might be a scenario where you might have to set up a company. This must be done using RapidStart Services, a tool designed categorically to improve the quality of implementation, shorten deployment times, introduce a repeatable approach to implementations and improve productivity by automating and simplifying recurring tasks. With the help of RapidStart Services, end users gain a comprehensive overview of the entire setup process of their new company through a worksheet, which facilitates setting up of tables generally involved in the configuration process of new companies. In the process, a questionnaire can be created by end users to guide customers, by collecting setup information. Customers have the option of either using the questionnaire to set up application areas or to open the setup page directly and do the setup there. Most importantly, RapidStart Services helps customers prepare the company using default data setup which can be customized and fine-tuned and by using RapidStart Services, they can also configure and migrate existing customer data into the new company.
Importing data from any system
While performing a D365 upgrade to Business Central, you might have to test your new Business Central company for which you will have to create an empty company and upload your data. Whichever finance-based solution your business works on currently, you must use that to transfer all relevant information about vendors, customers, inventory & bank accounts. You can do so by starting an assisted setup guide from the Role Center which helps transfer all business data from an Excel file or from other formats. Whatever extensions are available will eventually determine the types of files that you can upload. Additionally, master data and other transactional data can be imported from other finance systems based on the default configuration package in Business Central.
Go to the Configuration Packages page and import and validate data before applying the package. It is recommended that data migration wizards be used to import data from Dynamics NAV. The Inventory Setup page should be used to import item pictures. To import data to Excel, the configuration package in Business Central comprising 27 tables must be used, including payment terms, customer price group, shipment method, location, general ledger account, vendor, item, sales person, sales header, sales line, purchase header, purchase line, general journal line, item journal line, customer posting group, vendor posting group, inventory posting group, unit of measure, general business posting group, general product posting group, general posting setup, territory, item category, sales price and purchase price.
Using Intuit QuickBooks to import data
During a D365 upgrade to Business Central, you might have to import master data as well, which must be done using the data migration wizard. The wizard makes it relatively easy to migrate customers, vendors, items, chart of accounts, beginning balance transactions in General Ledger, on-hand quantities for inventory items, invoices, credit memos and payments from QuickBooks to Business Central. If your business happens to use QuickBooks, then relevant information can be exported and eventually uploaded to Business Central through the assisted setup guide. A few things you will have to be careful about is to make sure that account numbers are assigned to accounts in QuickBooks and that tax accounts are setup for relevant tax jurisdictions if transactions in QuickBooks have tax amounts before they can be posted.