How to Start Automating Your Plant: A Practical Planning Guide
Contents
1. Define the End Goal
Before any hardware is selected or any wiring is pulled, the most important step is answering a simple question: what do you need the automation to do?
This sounds obvious, but many automation projects run into trouble because the end goal was never clearly defined. The answer drives everything that follows — the hardware, the software, the budget, and the timeline.
Common automation goals include:
| Goal | What It Means in Practice | Complexity |
|---|---|---|
| Simple start/stop control | Replacing manual switches with a PLC and pushbuttons. Motors start, run, and stop in a defined sequence. | Low |
| Process interlocking | Preventing unsafe conditions — e.g., a pump cannot run unless a valve is open, or a mixer cannot start unless the lid is closed. | Low–Medium |
| Speed control | Using variable frequency drives (VFDs) to control motor speed based on process demand — pressure, flow, temperature, level. | Medium |
| Product tracking | Knowing where material is in your process at any given time. Barcode/RFID integration, batch tracking, lot numbers. | Medium–High |
| Closed-loop PID control | Automatically maintaining a setpoint (temperature, pressure, flow) by reading a sensor and adjusting an output in real time. | Medium |
| Recipe/batch management | Running different product formulations on the same equipment with automatic ingredient metering and sequencing. | High |
| Full process automation | End-to-end automated production with minimal operator intervention. Includes alarming, data logging, reporting, and potentially MES integration. | High |
2. Assess Your Current Infrastructure
Most plants already have some of the building blocks needed for automation — even if they are not connected to a control system yet. Before specifying new equipment, take an inventory of what you already have:
Electrical Infrastructure
| Item | What to Look For | Why It Matters |
|---|---|---|
| Motor starters / contactors | Are motors started by manual starters, across-the-line contactors, or soft starters? What voltage (480V, 208V)? | A PLC can command existing contactors if they have a 24VDC or 120VAC coil. No need to replace hardware that works. |
| Start/stop stations | Physical pushbutton stations at machines. Are they hardwired directly to starters or do they go through a relay panel? | These can often be rewired as PLC inputs, keeping the same operator experience while adding logic and interlocking. |
| Control power (24VDC) | Do you have 24VDC power supplies in your panels? | Most modern PLC I/O and field devices run on 24VDC. You may need to add power supplies if your plant only has 120VAC control power. |
| Solenoid valves | Are pneumatic or hydraulic valves controlled by 24VDC solenoids? | 24VDC solenoids can be driven directly from PLC digital output modules. 120VAC solenoids require AC output modules or interposing relays. |
| Sensors / transmitters | Proximity sensors, photoelectric sensors, level switches, temperature transmitters, pressure transmitters, flow meters. | Each sensor type determines what PLC I/O you need — digital inputs for discrete (on/off) signals, analog inputs for 4–20mA or 0–10V continuous signals. |
| Network infrastructure | Do you have Ethernet cabling in the plant? Managed switches? A plant network or just office IT? | Modern automation relies on EtherNet/IP. You may need dedicated switches and cabling for the controls network, separate from office IT. |
Feedback Devices — The Eyes and Ears of Automation
A control system is only as useful as the information it receives. Automation requires feedback — signals from the process that tell the PLC what is happening so it can make decisions. Without feedback, you just have a fancy switch.
| Feedback Type | Example Devices | PLC Input Type |
|---|---|---|
| Discrete (on/off) | Limit switches, proximity sensors, photoelectric sensors, pressure switches, level switches, motor overload contacts | Digital input (24VDC sink or source) |
| Analog (continuous) | Pressure transmitters (4–20mA), temperature transmitters (4–20mA), flow meters (4–20mA or pulse), level transmitters | Analog input (4–20mA or 0–10V) |
| Temperature (direct) | Thermocouples (Type K, J, T), RTDs (PT100, PT1000) | Thermocouple or RTD input module |
| Position / speed | Encoders (incremental or absolute), tachometers, linear transducers | High-speed counter or encoder input |
Not sure what you have or what you need?
This is exactly the kind of assessment we help with. A one-on-one conversation with one of our engineers can help you take inventory of your existing infrastructure, identify gaps, and figure out what is realistic for your budget and timeline. No obligation, no sales pitch — just practical guidance from 15 years of project experience.
3. Determine Your Control Strategy
Once you know what you want to control and what feedback you have (or will install), the next question is: how will the system be controlled?
| Strategy | Description | Best For |
|---|---|---|
| Manual with interlocks | Operators still push buttons to start and stop equipment, but the PLC enforces safety interlocks and sequencing. The operator is in the loop for every action. | Simple processes, retrofit of existing manual systems, environments where operators need direct control. |
| Semi-automatic | Operator initiates a sequence (e.g., "Start Batch") and the PLC runs a predefined set of steps automatically. Operator monitors and can intervene. | Batch processes, packaging lines, material handling systems. The most common approach for mid-size operations. |
| Fully automatic | The system runs continuously with minimal operator intervention. PLC manages all sequencing, setpoint control, alarming, and fault recovery. Operator role shifts to monitoring and exception handling. | Continuous process (water treatment, chemical processing, food production), high-volume discrete manufacturing. |
| Advanced / supervisory | Multiple PLCs coordinated by a supervisory system. May include recipe management (FactoryTalk Batch), process control libraries (PlantPAx), MES integration, or SCADA across multiple sites. | Large facilities, multi-unit operations, regulated industries (pharma, food/bev, oil & gas). Significant engineering investment. |
4. Choose Your Automation Platform
The automation platform is the hardware and software ecosystem that your control system will be built on. For most industrial applications in North America, this comes down to two primary manufacturers:
| Platform | Key Products | Strengths | Considerations |
|---|---|---|---|
| Allen-Bradley (Rockwell Automation) |
CompactLogix / ControlLogix PLCs, PowerFlex drives, PanelView HMIs, Stratix networking, Studio 5000 software | Dominant in North America. Largest integrator network. Extensive training resources. Strong in discrete and batch manufacturing. | Higher hardware cost than some alternatives. Studio 5000 licensing can be significant for small operations. |
| Siemens | S7-1200 / S7-1500 PLCs, SINAMICS drives, Comfort Panel HMIs, TIA Portal software | Strong globally. Competitive pricing. TIA Portal integrates PLC, HMI, and drive configuration in one tool. Strong in process industries. | Smaller integrator network in some US regions. Different programming workflow than Rockwell. |
Other platforms exist (Mitsubishi, Omron, Automation Direct, Schneider), but Allen-Bradley and Siemens account for the vast majority of industrial automation installations in the US. Your choice often depends on what your local integrators support and what is already installed in your facility.
5. Operator Interface & HMI
The Human-Machine Interface (HMI) is how operators interact with the automation system. It replaces (or supplements) physical pushbuttons and lights with a touchscreen displaying process graphics, alarms, setpoints, and controls.
| HMI Type | Examples | Best For | Cost Range |
|---|---|---|---|
| Panel-mount touchscreen | Allen-Bradley PanelView Plus 7, Siemens Comfort Panel, PanelView 800 | Single machine or small process. Mounted on or near the equipment. Simple graphics and navigation. | $1,000–$5,000 |
| PC-based HMI / SCADA | FactoryTalk View SE, Ignition by Inductive Automation, WinCC | Multi-machine, plant-wide visibility. Runs on standard PCs. Supports multiple simultaneous users. Historian, trending, alarming. | $5,000–$25,000+ |
| Web-based / mobile | Ignition Perspective, AVEVA Edge, custom dashboards | Remote monitoring, management dashboards, mobile access. Runs in a web browser — no client software to install. | $10,000–$50,000+ |
Ignition by Inductive Automation has become increasingly popular for plant-wide and multi-site applications. Its unlimited licensing model (no per-client fees) and built-in historian, alarming, and reporting make it cost-effective at scale. It connects natively to Allen-Bradley and Siemens PLCs and runs on standard servers or cloud infrastructure.
This is where it gets technical — and where we can help.
Choosing the right platform, selecting the right I/O, sizing drives and panels, and specifying an HMI architecture all require controls engineering experience. Our team has 15 years of hands-on project work across these platforms and can handle the technical heavy lifting — from hardware selection through programming and commissioning — so you can focus on running your operation.
6. Understand the Costs
Automation project costs vary enormously depending on scope and complexity. There is no single number that applies across the board, but understanding where the money goes helps set realistic expectations.
| Cost Category | What It Includes | Typical % of Total |
|---|---|---|
| Engineering & design | Electrical design, P&ID development, panel layout, programming, HMI graphics, network architecture | 25–40% |
| Hardware & materials | PLCs, I/O modules, drives, HMIs, panels, wire, conduit, sensors, power supplies, network switches | 20–35% |
| Panel fabrication | Building the control panel(s) — enclosures, DIN rail mounting, wiring, labeling, testing | 10–15% |
| Installation | Field wiring, conduit runs, device mounting, network cabling, power connections | 15–25% |
| Commissioning & startup | On-site testing, loop checks, tuning, operator training, documentation | 10–15% |
This is where having a clear scope and a well-prepared bid package makes a significant difference. When you approach an integrator with a defined scope, a preliminary I/O list, and a clear description of what you need the system to do, you get tighter bids and fewer change orders.
Our consulting service is specifically designed to help you build that bid package — so you can evaluate integrator proposals with confidence and avoid scope creep.
7. Regulations & Electrical Standards
Industrial automation projects must comply with applicable electrical codes and safety standards. These are not optional — they are legally required in most jurisdictions and practically required by insurance carriers.
| Standard | Full Name | What It Covers |
|---|---|---|
| NFPA 70 (NEC) | National Electrical Code | The foundational electrical installation standard in the US. Covers wiring methods, grounding, overcurrent protection, motor circuits, and equipment installation. All industrial electrical work must comply with the NEC as adopted by your local authority having jurisdiction (AHJ). |
| NFPA 70E | Standard for Electrical Safety in the Workplace | Defines safe work practices for electrical hazards — arc flash risk assessment, personal protective equipment (PPE) requirements, lockout/tagout procedures, and approach boundaries. Relevant during installation, commissioning, and ongoing maintenance. |
| NFPA 79 | Electrical Standard for Industrial Machinery | Applies specifically to industrial machinery and equipment. Covers control circuits, operator interfaces, wiring within machines, and safety-related control systems. Referenced by most machine builders. |
| UL 508A | Industrial Control Panels | Standard for the construction of industrial control panels. Covers component selection, wire sizing, short-circuit current ratings (SCCR), and panel labeling. Most integrators build UL 508A listed panels. |
| OSHA 29 CFR 1910 | Occupational Safety and Health Standards | Federal workplace safety regulations including lockout/tagout (1910.147), machine guarding (1910.212), and electrical safety (1910 Subpart S). Automation projects must not create new hazards. |
| ISO 13849 / IEC 62061 | Safety of Machinery — Safety-Related Control Systems | International standards for designing safety-related control systems. Defines Performance Levels (PLe) and Safety Integrity Levels (SIL). Applicable when the automation includes safety functions (E-Stop, guard monitoring, safe speed). |
8. The Project Lifecycle
A well-executed automation project follows a structured lifecycle. Skipping phases almost always results in cost overruns, schedule delays, or a system that does not meet expectations.
| Phase | What Happens | Deliverables |
|---|---|---|
| 1. Study & Scope Definition | Define the problem, establish goals, survey existing equipment, develop a preliminary scope of work and budget estimate. This is where you determine what to automate and why. | Scope document, preliminary I/O list, budget estimate, go/no-go decision |
| 2. Design & Engineering | Detailed electrical design, control panel layouts, P&IDs, network architecture, I/O assignment, hardware selection. The integrator produces the drawings and specifications that define how the system will be built. | Electrical drawings, panel layouts, I/O list, network diagram, BOM, functional specification |
| 3. Programming | PLC program development, HMI screen design, drive parameter configuration, alarm setup. May include simulation and factory acceptance testing (FAT) before going to the field. | PLC program, HMI application, drive configurations, FAT results |
| 4. Procurement & Fabrication | Ordering hardware (PLCs, I/O, drives, panels, sensors, cable, conduit). Control panel fabrication and pre-wiring. Lead times can be significant — plan ahead. | Control panels (built, wired, tested), field devices, cable/conduit |
| 5. Installation | Mounting panels, pulling wire, installing conduit, mounting field devices (sensors, transmitters, solenoids), network cabling. This is the most labor-intensive phase and typically requires coordination with plant operations to minimize downtime. | Installed and terminated field wiring, mounted devices, network connected |
| 6. Commissioning | Verifying every I/O point (loop checks), testing interlocks, tuning PID loops, verifying safety functions, testing alarm logic. The system is brought online incrementally — usually one section at a time. | Loop check sheets, commissioning punch list, tuning records |
| 7. Startup & Turnover | Running the system under production conditions. Operator training. Resolving punch list items. Handing over documentation, backup programs, and as-built drawings to the plant. | Operator training, as-built drawings, PLC/HMI backups, O&M documentation, warranty period begins |
9. Next Steps
If you have read this far, you are already better prepared than most first-time automation buyers. Here is what to do next:
- Write down your goals. What are the 2–3 things you want the automation to accomplish? Be specific about the outcomes, not the technology.
- Walk your plant with fresh eyes. Take inventory of existing starters, control devices, sensors, and network infrastructure. Photograph what you have. Note what works and what does not.
- Define the boundaries. What is in scope for this project? What is out of scope? Where does the automation start and stop? Being clear about boundaries prevents scope creep.
- Talk to someone who has done this before. A one-on-one conversation with an experienced controls engineer can save you weeks of research and help you avoid common mistakes. PLC Exchange offers free initial consultations specifically for this purpose — no obligation, no sales pitch, just practical guidance from 15 years of project experience.
You do not need to have all the answers before reaching out. In fact, the earlier you involve an experienced engineer in the conversation, the better your project outcomes will be.
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Ready to start planning your automation project?
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