Chapter 1 — Computing and service architecture

Learning outcomes

You will (1) describe the services a small healthcare business runs; (2) identify where patient data are stored and processed; (3) draw a simple service map.

1.1 The course and the case

Leila Haddad starts an eighteen-month technical course at the fictional Riverside Technical College. Her instructor, Mr. Daniel Okafor, pairs every topic with a placement at the fictional Marlow Dental Group, which runs eight clinics, treats about 45,000 patients and offers online booking with text-message reminders. Dental records include treatment notes, X-ray images and medical histories, which are data concerning health under Article 4(15) of the GDPR. Leila's role is technical: configuring, checking and documenting the systems that hold this information, always under supervision and using synthetic test data.

1.2 Services and components

Marlow's main services are a cloud practice-management system holding patient records, an imaging server in each clinic for X-rays, a booking website, an SMS gateway for reminders, email, and a payroll service for staff. Leila learns to separate a service, which is what users experience, from the components that deliver it: servers, databases, network links and vendor platforms. The booking service, for example, depends on the website, the practice-management system's interface and the SMS gateway, so a privacy problem in any one of them affects patients who book online.

1.3 Where data live

For each service, Leila asks three questions: what patient data does it store, where is it physically or logically hosted, and who can reach it. She finds X-ray images on local servers in every clinic, copies of referral letters in a shared mailbox and appointment lists exported to a spreadsheet by one receptionist. These locations matter because protection, retention and access requests must cover every copy, not just the main system. A record that exists in four places has four chances to be lost, kept too long or overlooked.

1.4 A first service map

Leila draws a service map with boxes for services, cylinders for data stores and arrows for flows, labelling each arrow with the data it carries. Mr. Okafor asks her to mark vendors in a different colour, because Marlow does not control their systems directly. The map shows that the SMS gateway receives patient names, phone numbers and appointment times, which reveals that a person is a dental patient. The map becomes the reference for later chapters, and Leila dates it so that changes can be tracked.

Worked example

Leila lists Marlow's services, separates services from components, finds patient data in local imaging servers, a shared mailbox and an exported spreadsheet, and draws a dated service map with vendors marked.

Synthetic case. Riverside, Marlow and all people are synthetic; GDPR Article 4(15) is real.

Errors and limits

A first map misses informal copies; interview staff as well as reading system lists.

Exercises

• EX001 — Health data. Why are dental treatment notes data concerning health?
  Show marking criteria

  Rubric: 3 = they reveal information about a person's health status;; 2 = mentions health;; 1 = vague;; 0 = none.
• EX002 — Service and component. What is the difference between a service and a component?
  Show marking criteria

  Rubric: 3 = a service is what users experience; components deliver it;; 2 = both;; 1 = one;; 0 = none.
• EX003 — Copies matter. Why does every copy of a record matter?
  Show marking criteria

  Rubric: 3 = protection, retention and access requests must cover all copies;; 2 = mentions copies;; 1 = vague;; 0 = none.
• EX004 — SMS content. What does the SMS gateway learn about patients?
  Show marking criteria

  Rubric: 3 = names, phone numbers, appointment times and that they are dental patients;; 2 = most;; 1 = one;; 0 = none.