Migrating to Microsoft Teams Phone in manufacturing means moving voice off legacy PBX systems while production keeps running. The safe approach is phased and site by site: audit the full voice estate, port numbers ahead of cutover, bring analog plant devices in over SIP, then migrate plant by plant as testing completes.
Manufacturing IT teams are managing two problems at once: infrastructure that was never designed to modernize, and operations that cannot afford to stop while modernization happens. 80% of organizations say outdated technology is holding back progress, and legacy voice is part of that estate. The stakes are concrete. Unplanned downtime costs manufacturers an average of $260,000 per hour, climbing to $2.3 million per hour in automotive. Voice infrastructure is rarely the headline cause, but it is often in the chain: a missed alarm, a failed escalation, a plant-floor system that cannot reach the people who need to respond. As Tom Arbuthnot of Empowering.Cloud puts it: “Manufacturing sites are some of the toughest environments for cloud voice. Between analog devices, overhead paging, PA systems, and safety-critical phone lines, it’s not your average Teams Phone deployment.”
With over fifteen years of experience in SIP and Microsoft UC, we've helped global manufacturers move to Microsoft Teams without putting production at risk. This guide shares our most important lessons, along with a checklist covering everything you need to consider as you plan your migration.
A successful Teams Phone migration in manufacturing begins long before technical deployment. The preparation phase matters more in this sector than almost any other, because the cost of getting it wrong is measured in production hours, not just IT tickets.
Proper planning enables swift progress. Project clarity is essential for gaining support from stakeholders who rarely sit in the same meetings: IT infrastructure teams, plant managers, facilities leads, and the supervisors who depend on the system every shift.
A good model is to think about your migration in four areas, the four must-knows:
Know what you have: Most manufacturers do not have a complete view of their voice estate. PBX systems installed decades ago, carriers inherited through acquisitions, analog devices nobody has audited. Mapping all of it is the essential first step.
Know what you want: Moving to Teams Phone is an opportunity to do things differently. Key decisions include your architecture model, number porting, device strategy, and how analog plant devices fit into the new environment.
Know where you want to deploy: Global manufacturers face significant variation between countries. Regulatory requirements, emergency calling rules, and coverage quality differ market to market. Plan for this early.
Before planning the future direction, assess the current setup. This is where manufacturing migrations most often go wrong. Plants run infrastructure installed 15 to 25 years ago, acquisitions add sites with unknown estates, and the result is a patchwork no single team fully understands.
We suggest a documented evaluation of your current telephony setup. This evaluation should catalogue:
Most large manufacturers run Avaya, Cisco, or Mitel systems installed decades ago. Avaya CM5 and Cisco CUCM 12.5 both passed end-of-life in 2025. If you are still running them, you have no manufacturer support, no security patches, and no compliance path without migration.
List every PBX, SIP trunk, gateway, and carrier relationship. Many multinational manufacturers manage a long tail of voice providers, and each brings its own contract, billing format, and support escalation path. When a site goes down on a Sunday night, you need to know exactly who to call.
Equipment differences affect migration planning, budget, and downtime coordination. Legacy systems require more preparation and testing than newer equipment.
Map the boundary between your corporate and plant-floor environments. Offices run Teams or Webex. Factory floors run whatever was installed when the plant was built, supplemented by radios, intercoms, and paging. These are two separate communication environments inside one business, and bridging them is central to the migration.
Map data flows for user data, call routing, and voicemail between systems.
Flag where voice infrastructure touches OT networks. A PBX or SIP trunk sitting across both IT and OT zones without proper segmentation creates an attack surface. PLCs, SCADA, and HMIs were built for availability, not security. Note these touchpoints now; they shape the security design later.
Plant-floor and analog devices: Catalogue every fax machine, tannoy and paging system, door entry system, and DECT handset embedded in plant operations. These devices keep production running and cannot simply be unplugged. They need a defined path into the new environment.
User experience across environments: A supervisor on the production floor and an analyst at head office use voice differently. Knowing which devices each group relies on lets you tailor the migration, training, and support to each.
Shared devices and common area phones: Conference rooms, reception desks, security gatehouses, and break rooms all need shared device accounts configured and uninterrupted service through the cutover.
Numbers: Document current number assignments and usage patterns, including shared numbers, emergency lines, and any numbers tied to alarm or monitoring systems.
A full PBX audit maps the existing environment in its entirety: every number, every device, every carrier relationship. For global manufacturers with years of accumulated complexity, that audit is often the first time IT has a complete picture of what they are actually running.
When migrating to Teams Phone, it's important to know what you want. This means informed decisions about architecture, device strategy, number allocation, and how the plant floor fits into the plan.
Consider the following:
Evaluate Operator Connect, Direct Routing, Calling Plans, or hybrid configurations. For manufacturers, the answer is usually a mix: Operator Connect where simplicity and speed matter, Direct Routing for sites or regions where Operator Connect does not reach or where onsite infrastructure is required. Both can run simultaneously within a single deployment.
Establish clear strategies for number allocation, porting, and management. Decide which devices will be supported, including desk phones, headsets, mobiles, and ruggedized handsets for the floor, and how they will be provisioned.
Plan for analog devices, not around them: Paging systems, door entry, fax, and DECT handsets do not need physical replacement to join the cloud voice environment. SIP Connect brings each device into the network through a single SIP endpoint. The plant floor keeps working while the migration continues in the background, and a plant manager can reach a Teams user at head office the same way they reach the machine next to them.
The shift from a legacy plant PBX to Teams Phone is a move towards an integrated communication environment that reflects how your business operates. Rather than replicating an old PBX configuration:
UCB, a global biopharmaceutical company, took this approach. Its voice estate spanned manufacturing plants, research facilities, and corporate offices, built up over years into on-prem SBCs, analog lines, and regional routing layers. Working with Pure IP, UCB moved to Microsoft Teams Phone via Operator Connect, consolidated telephony under one provider, and reduced its on-prem SBC footprint, keeping on-prem infrastructure only where regulation required it.
A manufacturer operating across 50 or 100 countries needs voice coverage for the full footprint, not just the easy markets. Automotive plants in Mexico, pharmaceutical sites in India, food processing facilities in Eastern Europe: these are core to how global manufacturing works, not edge cases.
Most carriers cover Western Europe and North America well. Coverage quality, local number management, and regulatory compliance in harder markets vary significantly, and the gaps tend to surface at the worst possible time.
Consider the following:
Assessing deployment locations and compliance needs: Map regulatory and compliance requirements for every country in scope before deployment begins. International calling restrictions, financial and data frameworks, and local telecom regulations can all force changes to network design and resource allocation.
Emergency calling compliance: For US sites, emergency calling is a legal requirement, not a best practice. A multi-building campus with mobile workers spread across production floors, warehouses, and outdoor staging areas cannot meet Kari's Law and RAY BAUM's Act requirements with a standard configuration. Every 911 call must deliver a dispatchable location accurate enough for emergency services to find the caller. Penalties run up to $10,000 plus up to $500 per day for the period of non-compliance. Audit your exposure now, not after an incident.
Requirements for onsite kit: In regions with unreliable connectivity or strict regulatory requirements, Direct Routing with onsite equipment may be necessary. Factor this into project timelines and budgets early.
Layered coverage for hard markets: Full PSTN replacement covers most of the footprint, Managed SBC services extend reach into harder markets, and BYOC integrates existing local carrier relationships where full replacement is not available. Pure IP scales coverage with your manufacturing footprint, across PSTN replacement, Managed SBC services, and BYOC.
This is where it all comes together. Manufacturing migrations carry more variables than most: live production, analog dependencies, OT security boundaries, and stakeholders who span the boardroom to the factory floor.
Phased projects are non-negotiable in this sector. Segmenting the rollout by site, region, or function minimizes risk, allows course corrections, and keeps production running throughout. Legacy PBX systems stay in place while migration happens in the background. A short-term managed SBC can support the transition at whatever pace the business requires, then leave with the migration: no stranded hardware, no lingering infrastructure costs.
Voice quality is a network outcome before it is a Teams outcome. A migration that ignores the connectivity underneath inherits every weak link already in the estate: congested plant links, single points of failure at remote sites, and backhaul that was never sized for real-time traffic.
Manufacturing makes this harder than most sectors. Corporate offices sit on managed circuits. Plants often run on whatever connectivity was available when the site was built, shared with OT systems that cannot tolerate jitter or contention. Treat both environments as one network, built for voice from the start, and a call from head office to the plant floor stays clear and reliable.
Local survivability matters here too. As Tom Arbuthnot of Empowering.Cloud notes:
Consider the following:
Resilience for production-critical sites: A single circuit carrying voice, data, and OT traffic together is a single point of failure. Map where a link failure would take voice down, and build in redundant connectivity and defined failover for the sites that cannot lose it.
Quality of service end to end: Real-time voice needs prioritization across the WAN, not just inside the LAN. Where plant links are shared or constrained, QoS and capacity planning decide whether voice holds up under load.
One managed network for the full footprint: A provider that runs the network as well as the voice service can hold performance to account across both, from corporate UC to the plant floor. The alternative is coordinating carriers, SBCs, and call quality across separate contracts and separate support desks.
Skills and knowledge must cover more than Teams and VoIP. Manufacturing migrations also demand familiarity with analog integration, OT network segmentation, and the operational realities of plant environments. Voice traffic crossing IT and OT boundaries needs encrypted transport, SIP over TLS, SRTP, defined routing, and access controls that standard deployments do not include.
Robust project management coordinates tasks, timelines, and resources across sites that may span continents and time zones.
In-house vs external resources comes down to cost, expertise, and control. In-house teams bring deep knowledge of plant operations; external specialists bring telecom and migration experience most IT teams have no reason to hold internally. Most projects end up being a mix of both.
Adoption in manufacturing means more than user training. Facilities leads need confidence that paging and door entry will keep working. Supervisors need to know they can reach maintenance during a line stoppage. Floor workers do not need to know how the infrastructure works; they need it to work. Engage these stakeholders early, not at go-live.
Project preparation: Ensure the project team has access to the right expertise, including compliance and regulatory advisors for every market in scope.
Scope definition: Audit existing systems and processes to identify areas of non-compliance, and set clear strategies to keep project scope aligned with compliance requirements.
Document existing telephony solutions and define key scenarios.
Assess sites for connectivity and scalability.
Catalogue plant-floor and analog devices.
Inventory paging and tannoy systems, door entry, fax machines, DECT handsets, and intercoms.
Identify shared devices and common area phones, including gatehouses and break rooms.
Understand how existing systems interact.
Review inherited and acquired estates.
Choose appropriate architectures and calling models.
Plan the analog transition.
Identify additional service requirements.
Phased projects
Network
Skills and knowledge
Project management
In-house vs external resources
Adoption considerations
Project preparation and scope
Manufacturing migrations carry more variables than most: live production, analog dependencies, OT security boundaries, and stakeholders who span the boardroom to the factory floor. Legacy PBX systems are embedded across plant sites, wired into paging infrastructure, analog devices, and operational workflows that cannot simply be unplugged. The migration has to happen around live production.
A full PBX audit maps the existing environment in its entirety: every number, every device, every carrier relationship. For global manufacturers with years of accumulated complexity, that audit is often the first time IT has a complete picture of what they are actually running.
Paging systems, door entry, fax, and DECT handsets do not need physical replacement to join the cloud voice environment. SIP Connect brings each device into the network through a single SIP endpoint.
If you already have SIP trunks or a SIP-capable PBX, get the port out of the way first. Your provider controls the routing between the legacy PBX and Teams, so you never have to sync the port with the cutover.
For manufacturers, the answer is usually a mix: Operator Connect where simplicity and speed matter, Direct Routing for sites or regions where Operator Connect does not reach or where onsite infrastructure is required. Both can run simultaneously within a single deployment.
A multi-building campus with mobile workers spread across production floors, warehouses, and outdoor staging areas cannot meet Kari's Law and RAY BAUM's Act requirements with a standard configuration. Every 911 call must deliver a dispatchable location accurate enough for emergency services to find the caller.
Phased projects are non-negotiable in this sector. Segmenting the rollout by site, region, or function minimizes risk, allows course corrections, and keeps production running throughout.
