Plant, business and IT–OT¶

You open the tap and water comes out. You never think about it. But in Palma, behind that tap there are more than 1,100 km of pipes, split into 600 small sectors, and a control centre where people watch pressures and flows on screens all day. In 2025 EMAYA, Palma's water company, said it had cut the water lost in leaks from 25% to 16%, after renewing pipes and installing digital meters. How do you find a leak under a street from a screen?

You find it because the plant (the pipes, pumps and meters) is talking to the business (the people who plan, pay and decide). This lesson goes down to the plant, names the technologies you find there, and then looks at the most valuable thing in a digital company: the connection between both halves.

The automation pyramid¶

In the city-builder game, the water plant has levels. Down at the bottom, valves open and pumps spin. A bit higher, automatic controllers keep the pressure right. Higher still, an operator watches the whole network on a big screen. At the top, the city hall decides budgets and plans. Companies with a physical operation are organised in the same layers.

The automation pyramid is a model that orders the technologies of a company in levels, from the machines at the bottom to the business at the top.

flowchart TB
    L4["<b>4 · Business: ERP</b><br>(the city hall)"]
    L3["<b>3 · Operations: MES</b><br>(the planning office<br>of the water plant)"]
    L2["<b>2 · Supervision: SCADA</b><br>(the control room)"]
    L1["<b>1 · Control: PLC</b><br>(the automatic controller<br>of each pump)"]
    L0["<b>0 · Field: sensors and actuators</b><br>(meters, valves, pumps)"]
    L4 --- L3 --- L2 --- L1 --- L0

Read it from the bottom up: the higher you go, the less real time and the more business view. Levels 0 to 2 are OT; level 4 is IT; level 3 is the bridge between them.

A real plant in Mallorca: TIRME at Son Reus¶

At Son Reus, near Palma, TIRME runs the plant that burns Mallorca's household waste and turns the heat into electricity. Its control system was supplied by the Japanese company Yokogawa, which published the case. According to that case, the plant has four lines, and the two newest ones generate 38 MW, enough electricity for about 53,000 households.

Here is what the published case lets you place on the pyramid:

Two lessons hide in this table. First, real plants do not always match the textbook: TIRME uses a large control system called a DCS that does the job of the PLCs and the SCADA together, and a plant information system rather than a factory MES. Second, look at level 4: the source does not say. In your project, what you find you cite; what you cannot find you label as hypothesis.

What a SCADA screen looks like¶

Inductive Automation, a company that makes SCADA software, keeps a public demo of a water treatment plant that you can open in the browser, with no account: Ignition Water Treatment Demo.

Open it and look for: the filters with their mode and status, the pumps in automatic mode switched On or Off, the tanks with their level, the flows in and out of the plant, and a trend chart of the last few days. Every one of those numbers comes from a sensor (level 0), passes through a controller (level 1) and appears on this screen (level 2). It is the city's info-view overlay, for real.

Business technologies¶

You met the ERP and the CRM in the previous lesson. Here is the full catalogue of the business side:

To select technologies means to choose, for one specific company, the ones it needs and the ones it does not. A four-person carpentry workshop does not need a MES; a water company cannot live without a SCADA.

Why connect IT and OT¶

Remember the hotel in the first lesson: the booking system (IT) switches on the air conditioning (OT) before the guest arrives. Generalise it:

Without the connection there are information islands: someone writes on paper what the machine says, and someone else types it into the computer. A mechanical water meter is an island: a person has to go, read it and write the number down. A digital meter with remote reading sends the number by itself.

How are they connected? Level 3 acts as the bridge, using standards such as OPC UA (an industrial standard for machines to share data securely) and MQTT (a lightweight messaging protocol for the internet of things), plus APIs and databases. That integration layer is software: work for developers like you.

The price: cybersecurity¶

Many OT devices are old and were not designed to be connected: few updates, default passwords. Once they share a network with the offices, a problem in IT can reach the plant. That is why the networks are separated, with firewalls between them, and access is controlled.

A real case: in May 2021, a ransomware attack (software that encrypts your files and asks for a ransom) hit the IT systems of Colonial Pipeline, which carries fuel to the east coast of the United States. There is no evidence that it reached the OT systems, but the company stopped the whole pipeline as a precaution, and it took about five days to restart. You will study cybersecurity properly in Unit 5.

End to end¶

A company is digitalised end to end when the whole journey, from the customer's order to delivery and the invoice, runs through connected systems, without typing any piece of data twice.

Follow an order in a biscuit factory:

flowchart LR
    A["<b>1 · Order</b><br>Website / CRM"] --> B["<b>2 · Plan and buy</b><br>ERP"]
    B --> C["<b>3 · Production order</b><br>MES"]
    C --> D["<b>4 · Make it</b><br>Sensors, PLC, SCADA"]
    D --> E["<b>5 · Batch and quality</b><br>MES"]
    E --> F["<b>6 · Ship and invoice</b><br>ERP"]
    F --> G["<b>7 · Delivery and after-sales</b><br>CRM"]
    G --> H["<b>8 · Results</b><br>BI dashboard"]

What does the company gain?

It also has a price: investment, training for the staff, and more exposure to cyberattacks. But a company with the whole journey connected can answer in hours what costs another one days.

In class: express X-ray of your company¶

In this session your group chose its company and each member did a first piece of research for one part. The parts are the four individual sections of Deliverable 1.

For each part, at least: the answer in 3–5 lines, one source (title, author or website, link and date you consulted it) and the word hypothesis in front of anything you could not find. Your name on your part. The group hands in one document on Classroom; each member is marked on their own part. No generative AI: this is an exercise in finding and citing.

For your project¶

This lesson launches Deliverable 1 · IT/OT X-ray, due Sunday 8 November 2026 at 23:59, with individual defences in session 9 (21 December 2026). Today's four parts are the first draft of its sections:

Key takeaways¶

• The automation pyramid, bottom up: sensors and actuators, PLC, SCADA, MES, ERP. Levels 0–2 are OT, level 4 is IT, level 3 is the bridge.
• Real plants, like TIRME at Son Reus, do not always match the textbook. What a source says you cite; what it does not say is a hypothesis.
• Selecting technologies means choosing and justifying, not listing everything.
• Connecting IT and OT sends data up (production, energy, breakdowns) and orders down; it removes information islands and needs cybersecurity.
• End to end: the whole journey from order to invoice through connected systems, typing each piece of data once.

Quick check¶

You have the whole picture of Unit 1. Now turn it into your group's first chapter: Deliverable 1 · IT/OT X-ray.