An ERP decision is rarely reversed inside five years. Most companies replace one after a painful audit, a failed month-end close, or the third time a salesperson promises stock that sold yesterday. The trouble is that almost every ERP demos well; the gap between vendors appears in month four of the implementation, when the partner's estimate has doubled and the chart of accounts is still being argued over. This ranking judges fifteen ERP platforms on what shows up in that period: how long rollouts actually take, how the license behaves as headcount grows, whether the company can get its ledger and item history out cleanly, and how locked in it becomes to one implementation partner. The list leans toward small and mid-sized buyers, and the largest vendors are ranked below independent options by design.
Visibility in this ranking can be paid for. Payment moves a vendor's position within the
shortlist; it never adds a vendor, and it never changes a word of the review. The largest vendors in ERP software
cannot hold places 1 to 3. How it works: placement disclosure ·
editorial process.
How we ranked these
Setup: the implementation, not the demo
We ask how long a realistic rollout takes for a company of fifty to three hundred people, and who has to do the work. Migrating open balances, item masters and customer records is the easy part; deciding costing methods, approval chains and the chart of accounts is what stalls projects. Products that ship with industry templates and sensible defaults score better, as do those a customer can partly configure without a partner billing every hour. We treat any vendor estimate of under three months for a manufacturer with healthy suspicion and discount marketing timelines that assume a clean data set. Parallel running, where the old system and the new one both process a month of live transactions, is the safeguard we look for vendors and partners to plan for.
The real price: license, partner and renewal
The subscription is typically a minority of the first-year spend. Implementation fees from a partner frequently match or exceed two years of licenses, and add-on modules for advanced inventory, planning or reporting appear on the second quote, not the first. We look at the license model (per named user, by transaction volume, or per app), whether list prices are published, how many light users can be added cheaply, and what customers report paying at renewal. Contracts with annual uplift clauses, or that price the platform fee by total company revenue, are marked down. We also ask whether storage, sandboxes and test environments cost extra, since those appear only once the project is underway.
Getting your data out: ledgers, items and history
An ERP holds the only complete copy of a company's transaction history, so we check how that history leaves. Can an administrator export the general ledger with full detail, the item master with units and costs, and open orders, without paying for a separate connector? Is there a documented API, ODBC access or a database the customer controls? On-premise and open-source products do well here by default. Cloud vendors that meter API calls or charge extra for reporting database access lose points, because the same limits bite during a BI project and again at migration. Document attachments such as scanned invoices and delivery notes matter as well, and some vendors make them hard to extract in bulk.
Independence from the vendor: partners, code and upgrades
ERP lock-in has two layers. The first is the vendor: proprietary scripting languages and data models make every customization a sunk cost. The second is the implementation partner, who often owns the add-ons, the hosting and the only person who remembers why a posting rule was changed. We favor products with open data models, several competing partners in most regions, and upgrades that do not break extensions. Being able to move the system to a different partner, or run it in-house, without rebuilding customizations is the practical test. We also check whether customizations live in documented extension layers or are written directly into core objects.
Who it's for: size, industry and complexity
The honest answer to which ERP is best depends on three facts: headcount, number of legal entities, and whether the company makes things. A single-entity distributor with forty staff needs something very different from a make-to-order manufacturer with three plants, or a funded software firm with subsidiaries in four countries. Each entry below names the company it suits and the one it does not. We rank for small and mid-sized buyers; a global enterprise with SAP S/4HANA on the shortlist is outside this guide's scope. Where a vendor sells distinct editions by industry, we judge the edition a typical buyer would actually receive.
The 15 tools, reviewed
#1 Odoo
Modular ERP with an open-source core, priced per user · Belgium · odoo.com
Open-source core Published prices Build it in stages
Odoo is the broadest ERP here that a twenty-person company can realistically start alone, with accounting or stock on a weekend and manufacturing six months later, without ever renegotiating a license. The apps share one database and one interface, so a sale confirmed in Sales reserves stock in Inventory and posts to Accounting without a connector in between. Community edition code is LGPL, which means the data model is public and a local developer can read it. For a small or mid-sized business that wants one system instead of five, it is the most sensible opening move in 2026.
Where it falls short
Each app is shallower than a specialist: landed-cost handling and advanced MRP scheduling work but need configuration or partner modules, adding a second company to a paid database moves you to the Custom plan, and multi-company consolidation is an Enterprise-only feature. Custom modules must be updated by the customer before each yearly version upgrade, and upgrade work on a heavily customized database is billable. Quality among Odoo partners ranges from excellent to alarming.
Wrong for
A discrete manufacturer with finite-capacity scheduling needs, or a group with a dozen legal entities and complex intercompany eliminations, will hit Odoo's limits early and should shortlist Epicor Kinetic or NetSuite instead.
Pricing: Published per-user plans covering all apps, a free plan limited to a single app, and a Custom plan for Studio, external API access and on-premise hosting. (free plan)
Visit Odoo →
#2 Acumatica
Cloud ERP licensed by applications and resources, not users · United States · acumatica.com
Unlimited users Industry editions Partner-delivered
Acumatica's pricing is the structural reason it ranks this high. Because the license is priced by applications and by resource levels tied to transaction volume and storage, a company can give every picker, project manager and approver a real login instead of rationing seats, which is how ERP data actually stays current. The industry editions for distribution, manufacturing and construction are built on one codebase, and the browser interface is consistent across them. Customers can also choose to run it in Acumatica's cloud or on their own infrastructure, which is rarer than it should be among cloud ERPs.
Where it falls short
All sales and most implementations go through value-added resellers, so the quote, the timeline and the quality of the rollout depend on which partner answers the phone. Reporting beyond the built-in generic inquiries usually means learning its report designer or paying for a BI connection. The ecosystem of third-party add-ons is thinner than Business Central's or NetSuite's.
Wrong for
A five-person firm with simple books is paying for machinery it will not use; Odoo or plain accounting software fits better. A process manufacturer with formula and batch rules should look at Sage X3.
Pricing: Annual subscription priced mainly by the applications licensed, plus resource levels sized to transaction volume and the deployment choice, with unlimited users; sold exclusively through partners. (none)
Visit Acumatica →
#3 Epicor Kinetic
Manufacturing ERP with deep job and shop-floor control · United States · epicor.com
Discrete manufacturing Shop-floor control Cloud or on-premise
Epicor Kinetic understands a job shop. Quotes turn into jobs with routings, operations clock labor and material against those jobs from the shop floor, and the scheduling board shows which work center is the bottleneck next Tuesday. The product configurator handles engineer-to-order variations that general ERPs push into spreadsheets. For a manufacturer between roughly fifty and a few thousand employees whose margin depends on knowing the true cost of each job, it is the specialist pick on this list.
Where it falls short
The interface still mixes the modern Kinetic screens with older forms, and training is not optional. Implementations commonly run six to twelve months, and the configuration choices made early, such as costing methods, are expensive to reverse. Finance and HR functions are serviceable but not why anyone buys it.
Wrong for
Distributors, retailers and service firms get little from its manufacturing depth and pay for it anyway; Acumatica or Business Central suit them better. A ten-person workshop should start with MRPeasy.
Pricing: Quote only, sold as a cloud subscription or a perpetual license, with implementation services from Epicor or its partners. (none)
Visit Epicor Kinetic →
#4 NetSuite
Oracle's cloud ERP for scaling and multi-entity companies · United States · netsuite.com
Multi-entity Large app ecosystem Renewal price risk
NetSuite has been cloud-native since 1998, and the payoff is visible in upgrades: two releases a year land on every customer without a migration project. OneWorld handles subsidiaries in different currencies and tax regimes, which is why so many funded startups move onto it before an audit or an acquisition. SuiteScript and a large SuiteApp marketplace cover most gaps, and there is a deep pool of consultants and admins who know the platform.
Where it falls short
The first-year price is negotiable; renewals are where Oracle claws it back, and customers regularly report double-digit uplifts. Core inventory management is part of the base platform, but useful capabilities, including SuiteAnalytics Connect for ODBC access, are separately priced optional modules. The saved-search reporting model is flexible but opaque, and customizations accumulate into something only one admin understands.
Wrong for
A single-entity company under about fifty staff will pay enterprise money for multi-subsidiary machinery it does not need, and should compare Odoo or Acumatica first.
Pricing: Annual contract combining a base platform fee, per-user licenses and add-on modules, quoted by Oracle sales; no published price list. (none)
Visit NetSuite →
#5 SAP Business One
SAP's partner-sold ERP for small and mid-sized firms · Germany · sap.com
SAP ecosystem Partner-delivered SQL Server or HANA
Business One is a compact, well-understood product with a huge installed base across Europe and Asia. Its strongest use case is the daughter company of a group already running SAP S/4HANA: the head office gets a familiar data model and integration options, and the local business gets an ERP sized to twenty or two hundred users. Inventory, batch and serial tracking, and MRP are all there without add-ons.
Where it falls short
Almost everything depends on the partner: pricing, hosting, support response and the add-ons that fill gaps, which tend to come from a partner's own catalogue and bind the customer to them. The desktop client feels old next to browser-first rivals, and SAP's own cloud roadmap points customers toward S/4HANA rather than investing heavily here. Moving a Business One company to another partner is possible but painful when that partner wrote the add-ons.
Wrong for
A company with no SAP connection and no strong local partner gains little from the brand; Acumatica or Business Central give comparable scope with a more modern client.
Pricing: Named-user licenses, bought outright or on subscription through an SAP partner, running on Microsoft SQL Server or SAP HANA. (none)
Visit SAP Business One →
#6 Microsoft Dynamics 365 Business Central
Microsoft's small and mid-sized business ERP · United States · microsoft.com
Microsoft ecosystem Published list prices Partner-delivered
Business Central descends from Navision, a product with decades of mid-market use, and it shows in the accounting core and the depth of its inventory and warehouse handling. The integration with Excel, Outlook, Teams and Power BI is the practical selling point: finance teams edit journals in Excel, and approvals happen in Outlook. Its list prices are public, which remains unusual among full ERPs, and AppSource offers extensions for most local tax and banking needs.
Where it falls short
Manufacturing in the Premium tier is adequate for assembly and simple production, not for complex job shops. Every serious deployment needs a partner, and partner quality varies widely. Extensions written in AL must be maintained through Microsoft's twice-yearly updates, and heavy customization makes those updates a recurring project.
Wrong for
A company standardized on Google Workspace loses the main reason to choose it. Manufacturers with complex routings should compare Epicor Kinetic; very small firms should look at Odoo.
Pricing: Published per-user monthly prices in Essentials and Premium tiers, with cheaper Team Members licenses for light users; partners add implementation fees. (free trial)
Visit Microsoft Dynamics 365 Business Central →
#7 Infor CloudSuite
Industry-specific cloud ERP suites · United States · infor.com
Industry suites Multi-tenant cloud Enterprise sales cycle
Infor, owned by Koch Industries since 2020, builds separate suites for industries such as industrial manufacturing, food and beverage, distribution and healthcare rather than one horizontal ERP. The payoff is fewer customizations inside those industries: a food manufacturer on M3 gets catch weights and lot traceability as standard. The ION integration layer and multi-tenant hosting give it a cloud story comparable to NetSuite's in larger deployments. For a mid-sized food, fashion or industrial company with a clear match, that head start can outweigh the heavier sales process.
Where it falls short
Picking the right CloudSuite is itself a decision that needs a sales engineer, and the product names can be confusing. Pricing is opaque, contracts are long, and implementation typically runs through Infor Services or a small number of partners. Smaller customers report feeling like a low priority, and account managers change often. Customizing multi-tenant CloudSuite is restricted to extensions, so an old on-premise Infor customer may find favorite modifications cannot be carried across.
Wrong for
Any company under about a hundred employees, or one without a clear industry match, is better served by Acumatica, Business Central or Odoo.
Pricing: Quote only, multi-tenant subscription per industry suite, typically with a multi-year contract and separate implementation. (none)
Visit Infor CloudSuite →
#8 Sage X3
Mid-market ERP for process manufacturing and distribution · United Kingdom · sage.com
Process manufacturing Lot traceability Multi-entity finance
Sage X3 is at its best in a regulated process business: a food or chemicals producer that needs recipes, batch control, expiry dates and a recall trace from raw material to customer. Multi-legislation support lets one instance run entities in several countries with local ledgers, which is why it appears in groups spread across Europe and Africa. For those buyers it does the job at a lower cost than Infor. Traceability reports are available as standard rather than as a paid add-on.
Where it falls short
Sage's marketing and investment clearly favor Sage Intacct, and X3's interface and release cadence reflect that. Implementations are partner-run and often long, and finding experienced X3 consultants is harder outside Europe. Reporting leans on add-ons and Excel, and multi-site companies frequently add a separate BI tool within the first year.
Wrong for
Discrete job shops fit Epicor Kinetic better, and a company that mainly needs strong cloud financials should look at Sage Intacct or NetSuite instead.
Pricing: Quote only, subscription or perpetual license per user through Sage partners, hosted or on-premise. (none)
Visit Sage X3 →
#9 ERPNext
Fully open-source ERP on the Frappe framework · India · frappe.io
GPL open source Self-hostable Small partner network
ERPNext offers a complete ERP without license fees: double-entry accounting, multi-warehouse stock, bills of materials, work orders, and payroll through Frappe HR. All code is on GitHub under GPLv3, so nothing sits behind an enterprise edition wall. Customization happens through doctypes and scripts in the Frappe framework, which a Python developer can learn in weeks. For a company with in-house technical skill and tight cash, it is a serious option rather than a toy.
Where it falls short
Without a developer or a good partner, setup mistakes pile up quickly, and community forums are the default support channel. Localization for payroll and tax outside India varies in quality. Major version upgrades have historically required careful testing of custom apps.
Wrong for
A business with no technical staff and no appetite for managing a server should pay for Odoo or Acumatica, where support is part of the price.
Pricing: Free to self-host under GPLv3; managed hosting on Frappe Cloud is billed per site with published monthly plans, and paid support is separate. (open source)
Visit ERPNext →
#10 MRPeasy
Browser-based manufacturing ERP for small factories · Estonia · mrpeasy.com
Small manufacturers Published prices Fast rollout
MRPeasy fills the gap between spreadsheets and a full ERP for small factories. Bills of materials, routings, a production schedule and material requirements planning are all in place on the first day, and many customers configure it themselves without a partner. Prices are published and monthly, so a small manufacturer can trial it on real orders before committing. The company is based in Tallinn and sells worldwide online, with support in English.
Where it falls short
The built-in standard accounting covers a ledger, balance sheet and P&L but stays basic, and many customers pair it with QuickBooks or Xero, which leaves two systems to reconcile at month end. Multi-entity setups, complex costing and heavy customization are outside its scope, and the reporting is basic. Support runs through an in-app ticket system, with paid training and Advanced Support plans, rather than through local partners.
Wrong for
A distributor or retailer gets little from it, and a manufacturer planning several legal entities within a few years should start on Epicor Kinetic or Acumatica.
Pricing: Published per-user monthly tiers from $49 Starter to Unlimited; even Starter includes CRM, purchasing and standard accounting, while higher tiers add a product configurator, multiple production sites and the API; free trial, no contracts. (free trial)
Visit MRPeasy →
Configurable International Smaller ecosystem
Priority has been built and sold from Israel for decades and now serves mid-sized companies across Europe, the US and Asia. Its low-code tools let an in-house admin add screens, fields and mobile forms without vendor involvement, and the same platform covers manufacturing, distribution and services. For a company with offices in several countries, the multi-currency and multi-language support is mature. Pricing is quoted per user, and customers often praise the vendor's direct support team.
Where it falls short
Brand recognition is low in North America, so both partners and experienced consultants are harder to find than for Business Central or NetSuite. Some modules, such as advanced warehouse management, are less deep than specialists, and documentation is uneven. Customers outside Israel and a few European markets may find local tax and payroll support depends on a single reseller.
Wrong for
A buyer who wants the largest pool of consultants and add-ons should pick Business Central or NetSuite; a small company on a tight budget is better off with Odoo.
Pricing: Quote only, sold as Commercial or Manufacturing plans, with modules such as warehouse management, project management, the API and the mobile app generator priced as add-ons. (none)
Visit Priority ERP →
#12 Syspro
Manufacturing and distribution ERP from Johannesburg · South Africa · syspro.com
Manufacturing and distribution Regional partner strength On-premise option
SYSPRO has spent decades selling to manufacturers and distributors, and customers tend to stay for a long time, which says something about day-to-day fit. It is strong in food and beverage, electronics and machinery, and its direct presence in South Africa, Australia and North America means a customer can deal with the vendor itself rather than only a reseller. Its consultants tend to know manufacturing well. It sits below MRPeasy and Priority because ending its upfront and annual licenses forces every existing customer onto a named-user subscription, a vendor-imposed change that weighs on both price and independence.
Where it falls short
Outside its core regions the partner pool is small, and the user interface and reporting feel less current than Acumatica's. Cloud deployment is largely hosted rather than true multi-tenant, so upgrades still need planning. Syspro is ending its upfront and annual license fee model in late 2026, so existing license holders must sign a named-user subscription or lose access. Third-party add-on choice is limited, and new staff mostly learn it on the job.
Wrong for
A buyer with no manufacturing floor, or one in a region with no SYSPRO partner nearby, should look at Business Central or Acumatica instead, where consultants are easier to hire.
Pricing: Quote only, named-user subscription sold directly and through partners, deployed on-premise or in Syspro Cloud on Azure; the upfront and annual license fee model ends in late 2026. (none)
Visit Syspro →
#13 Exact Online
Cloud accounting and ERP for Benelux SMEs · Netherlands · exact.com
Benelux focus Accountant collaboration Cloud only
In the Netherlands and Belgium, Exact Online is often the ERP a small company already half uses, because its accountant files the VAT return from it. Packages are cut by business type: a wholesaler gets ordering, purchasing and stock on top of the ledger, a manufacturer gets bills of materials and production orders, and a services firm gets time and project billing. Bank feeds, local tax reporting and accountant access come standard, and an app marketplace fills gaps such as webshop links. For a Benelux company of five to fifty people, it removes the need for a partner-led project altogether.
Where it falls short
Outside the Benelux it loses most of its advantage, since localizations, partners and the accountant network thin out quickly elsewhere. The manufacturing module handles straightforward assembly but not complex routings or capacity planning. Customization is limited to what the API and marketplace apps allow, and costs rise package by package as users and modules accumulate.
Wrong for
A company with operations in the United States or across many non-Benelux countries, or a manufacturer with complex routings, should shortlist Odoo, Business Central or Acumatica.
Pricing: Published monthly packages by business type (accounting, trade, manufacturing) in Essentials to Premium tiers, with extra users and modules added on; free trial. (free trial)
Visit Exact Online →
Job shop Direct implementation Quality management
Global Shop Solutions sells to machine shops, fabricators and make-to-order plants, mostly in North America, and does so without a partner channel: the vendor itself implements, trains and supports. The product is one database spanning estimating, job costing, shop-floor data collection, scheduling, quality, inventory and the ledger, so an estimator can see what the last similar job really cost before quoting the next one. Training is a large part of the package, delivered on site and online. For a job shop of fifty to three hundred people that has been burned by a partner-led rollout, the direct model and narrow focus earn it this spot.
Where it falls short
The interface is dense and older in style than Acumatica's, and users need real training before they move quickly. Process manufacturers and distributors will find little tailored to them. Pricing is quote only, and because there are no independent partners, a company that falls out with the vendor has no second source of consultants.
Wrong for
A distributor, a service business or a small maker selling through Shopify would pay for depth it never touches; Acumatica, Odoo or Katana fit those profiles.
Pricing: Quote only, on a concurrent-user model with an upfront fee plus a quarterly charge that covers updates and support; deployed in the cloud or on premises. (none)
Visit Global Shop Solutions →
#15 Katana
Cloud inventory and manufacturing software for small makers · Estonia · katanamrp.com
Make-to-stock Webshop orders Accounting sync
Katana is what many small manufacturers buy instead of a full ERP, and for a brand producing cosmetics, furniture or apparel in batches it covers most of the operational ground. Sales orders arrive from Shopify or Amazon, the system checks raw materials against multilevel bills of materials, and production is scheduled by priority, with a shop-floor tablet app sold as an add-on. Costs roll up from materials and operations, while the ledger stays in QuickBooks Online or Xero through a sync. Setup takes weeks rather than months, with no partner needed, which is why it earns a slot on a list otherwise full of long implementations.
Where it falls short
Finance is handed to the accounting package, so multi-entity consolidation, fixed assets and serious cost accounting are out of reach. Scheduling ignores finite capacity at work-center level, and routings, the shop-floor app, warehouse and traceability features are separate monthly add-ons on top of Core. The usage-based bill climbs with order volume and extra locations, and deep customization is not on offer.
Wrong for
A job shop quoting custom parts, or any company that needs one ledger across several entities, should look at MRPeasy, Global Shop Solutions or Acumatica instead.
Pricing: Free plan capped at 30 SKUs; the Core plan starts at $299 a month with unlimited users and scales with delivered sales orders and locations, with paid add-ons for manufacturing routings, the shop-floor app, warehouse and traceability. (free plan)
Visit Katana →
Questions and answers
What is the best ERP software in 2026?
For most small and mid-sized companies, Odoo is the best starting point: it can be adopted one app at a time, prices are published, and the open-source core means the data model is not a black box. Acumatica is the better pick for a distributor or contractor with many occasional users, because its license does not charge per seat. Epicor Kinetic is the right choice for a make-to-order manufacturer that needs real job costing and shop-floor control rather than a finance system with manufacturing added.
At what size does a company actually need an ERP?
Headcount is a poor trigger. The usual signals are operational: inventory counts that never match the books, month-end close taking more than a week, several systems re-keying the same order, or a second legal entity. Some twenty-person manufacturers need an ERP; some two-hundred-person service firms do fine with accounting software, a CRM and a project tool.
How long does an ERP implementation take?
For a small company on Odoo or MRPeasy with simple processes, two to four months is achievable. Mid-market rollouts of Acumatica, Business Central or NetSuite commonly take four to nine months, and manufacturing deployments of Epicor, Infor or SYSPRO often run beyond that. The main variables are data quality, how many processes are redesigned, and the availability of the internal project lead. Projects where that person also keeps their day job almost always run late, so budget for backfilling their role during the busiest months.
Is cloud ERP better than on-premise ERP?
Cloud removes server management and makes upgrades routine, which matters for a company without IT staff. On-premise, or a private hosted instance, still makes sense where plants have unreliable connectivity, regulation requires data residency, or heavy customization would break under forced upgrades. Several products here, including Acumatica, SAP Business One, SYSPRO and Epicor, let the customer choose.
What is the difference between ERP and accounting software?
Accounting software records the financial result of transactions: invoices, bills, payments, the ledger. An ERP also runs the operational transactions that create those results, such as purchase orders, stock movements, production orders and shipments, so the ledger updates as work happens. A business with no inventory and one entity often does not need ERP. Many companies move up in stages: accounting software first, then a stock or production tool connected to it, and a full ERP only when the connectors become the problem.
Can an open-source ERP handle a real business?
Yes, with conditions. ERPNext and the Odoo Community edition both run companies with hundreds of employees. What they do not include is the vendor support, hosted infrastructure and partner accountability a commercial contract buys, so the company needs a developer on staff or a paid partner. The license saving is often spent on that expertise, but the business owns the result and can change partners freely.
Why do ERP projects go over budget?
Usually because scope grows during implementation. Processes nobody documented are discovered, data cleansing takes longer than planned, and each customization adds testing on every future upgrade. Fixed-scope contracts with a named change-control process, and a willingness to adapt some processes to the software, keep overruns in check. So does postponing nice-to-have reports and integrations until a second phase, after the ledger and stock have been stable for a quarter.
Should a manufacturer choose a manufacturing ERP or a general one?
A company that builds to order, tracks labor by job, or plans capacity across work centers benefits from a manufacturing-first product such as Epicor Kinetic, SYSPRO, Global Shop Solutions or MRPeasy; a small maker selling mostly through a webshop can start lighter with Katana. A firm that assembles simple kits or outsources production can usually use the manufacturing module of a general ERP such as Business Central or Odoo.
How do ERP licenses charge for occasional users?
It varies widely. Business Central sells cheaper Team Members licenses for people who approve and view; NetSuite has limited-access roles; Acumatica does not charge per user at all. Before signing, count the warehouse staff, approvers and managers who need only occasional access, and price them separately in every quote. Light users often outnumber full users two to one in a distribution business, so the difference is material.
Can we keep our existing warehouse or e-commerce tools with a new ERP?
Usually, through an integration. Most ERPs here have connectors for Shopify, Amazon and common shipping tools, and several dedicated warehouse systems integrate with NetSuite, Business Central and Acumatica. The questions to settle are which system owns stock quantities, how often it syncs, and who maintains the connector when either side changes its API. A clear owner for each piece of data avoids the classic problem of two systems overwriting each other.
How hard is it to switch ERP later?
Hard, which is why the independence test matters. Open transactions, item history and customer terms all have to move, and any customization must be rebuilt. Companies that keep documentation, own their code, and export full ledger detail regularly find a later switch far less painful than those relying on a single partner's memory.
