Upgrading your Magento platform from Magento 1.x to 2.x requires a bit of planning, content adjustment if a new Theme is being considered as part of the effort, and some training on the administrative side with the new features and capabilities.
Magento Extensions and Custom code
Capturing your current store's features is a key starting point. Finding the equivalent capabilities for integration within the 2.x environment will most likely be a close but not exact match. Magento 2.x is a much more capable eCommerce platform, and while it is open source there are usually some customization incorporated which require to take note of. To do this assessment you might need a Magento Expert, or have access to a development team that can do this task thoroughly. While Magento 2.x is a higher-performance online store, the site offers new features outside of what Magento 1.x offered - a final review of the Magento 2.x package vs. Magento 1.x would be beneficial as a way to size up the upgrade.
Building a Magento 2 staging site
While it being obvious to prepare a server to host your new environment, ensuring the resources to host are sized up correctly when it comes to server requirements and OS. With the assessment made above, scoping out how the assets will fit within the desired Magento Theme will be the first step. The installation of the equivalent Magento Extensions, and re-fitting any custom additions that were made on the previous system to accommodate reports/features or page layout considerations need to also be fitted (including Database changes). Graphic design skills will be required most likely to bring in your brand, your look/feel for the customer experience you are looking to deliver for the ultimate online shopping experience.
In some cases, an ERP system integration is connected to a store (Enterprise Resource Planning - ERP), where that connection will be upgraded to a new extension - that will also require a staging account on the ERP system or ERP software.
Migrating the data utilizes a Data Migration Tool that's available for use. Depending on what is planned to be transferred (customers, products, orders, reviews, etc.) some adjustments will most likely need to be made. A limited transfer version of the tool should be prepared since that will require fine-tuning.
Any financial connections will also require the same staging requirements as the ERP system, where a staging account will be needed to test with
Preliminary assessment
Now that your staging and preparation with some limited testing has been made, assessing the system is important to identify any gaps, areas of instability, workflow process, department requirements, and check that all Magento API functionality, Data flows, and capabilities are meeting the Magento Migration plan.
Magento Data Migration
When the assessment is concluded and is satisfied that the functionality based on minimal data to work with, migrating the full store over to the new staging site will take some effort. Database checks on how many records are in one location vs. the other while testing the new store thoroughly will take some time. This is a dry-run to test that the migration tool can work at full transfer capacity and if it can bring everything needed to do a 1-night move-over migration.
Testing the Dry-run
Testing is a critical component. Even if all the assets are not in place yet, functionality for ordering, payment processing, shipping and logistics, reporting, and all that's associated with the business needs a thorough review. Historical data reports can be generated in Magento 1.x and be compared with Magento 2.x. They should match, and if they do not, then it requires investigation on what is causing the issue. A full report of all areas is required to be put together, including transfers to ERP systems and Financial systems - which will require similar historical report checks between the live account and the staging one.
Planning your Migration date
When the Dry-run verifications pass, a date needs to be set where it will least impactful to the business. A checklist of what tasks are needed in transferring the live data over, doing basic checks, to then re-pointing the domain. It is useful to have the new Magento 2.x live site to be separate from the Magento 2.x staging site for comparative reasons. Since going forward your development area will be in 2.x, the staging area is where new development will take place. As for additional preparations, a roll-back plan also needs to be put in place if there is a critical issue in the migration. All scenarios require consideration, keeping customer impact low, and ensuring the business impact is negligible.
Ensuring that the Live site server is finalized and ready for the final Magento Data Migration, including that all Theme and other development being complete, where the live site will be configured and connected to 3rd-party live accounts (Payments, ERP, Financial, 3PL) - All must be listed, ready to execute efficiently.
Going Live: Magento Migration and checks
With the migration being executed, checks between the Magento 1.x (last records) to Magento 2.x will be required to ensure that the data structure has migrated over fully. Basic functionality between all systems needs to be made, and when the Magento 2.x Live server is configured and live - test orders will need to be made with live payments. Every system needs checking, including all 3rd party systems, ensuring that the data transfers are taking place and that reports are all working. Checking all workflows, and critical functionality being first priority, secondary functionality checking as well. Every department down to printing shipping labels will need to be verified. With most migrations, there will be a small "to do" list of adjustments - which leads to the next section.
Post Migration "to do's"
With the hurdle being behind you migrating to Magento 2.x live, polishing the migration still requires a final effort before going into maintenance mode. Cleaning up of all test data, test accounts, test products, and any database cleanup might be required - this is surgical in nature, and must be done with care. Checking that all redirects (if any) have been done and that all SEO metrics are looking healthy - doing an SEO Audit would benefit to check that there are no issues detected that require correction.
Magento developers and Magento Experts
If you are a small business, you will most likely be requiring additional help to get you through the migration of your Magento website. Small business owners often have a Magento resource they lean on when it comes to maintenance. A Magento migration is a step up when it comes to effort in website development in comparison to maintenance. The eCommerce store has to deliver on its promise to replace and perform better and quicker than its predecessor, all the while improving the bottom line of the business. Especially when dealing with an ERP solution involved, and other integrated systems like 3PL and Financials.
Magento Maintenance and Hosting
If your Magento store requires maintenance, hosting, upgrading, or customizing, we have the staff and toolsets to keep your system running smoothly and with efficiency. Identifying tasks, issue reports, small enhancements can be defined in our monthly Service Level Agreements (SLA's). Making it easier to run the business, and having a partner within reach.
If Magento is for you and your business - to either maintain, develop or migrate to and from, reach out to us so as to scope your needs.
For Magento Migration reference: https://devdocs.magento.com/guides/v2.4/migration/migration-plan.html