Chapter 25 — Design studio I
Lesson map
Lesson 25 published. Map, example, EX049.
flowchart TD
N0["Learning outcomes and connection"]
N1["25.1 What a studio is"]
N2["25.2 The brief"]
N3["25.3 Generating alternatives"]
N4["25.4 Weighted evaluation"]
N5["25.5 Presenting and responding to review"]
N6["25.6 Practical activity"]
N7["Chapter synthesis"]
N0 --> N1 --> N2 --> N3 --> N4 --> N5 --> N6 --> N7
N7 --> EX["Worked example"]
EX --> Q["Exercise EX049"]
Logical drawing
flowchart LR
N0["Learning outcomes and connection"]
N1["25.1 What a studio is"]
N2["25.2 The brief"]
N3["25.3 Generating alternatives"]
N4["25.4 Weighted evaluation"]
N5["25.5 Presenting and responding to review"]
N6["25.6 Practical activity"]
N7["Chapter synthesis"]
N0 --> N1 --> N2 --> N3 --> N4 --> N5 --> N6 --> N7 --> Q["EX049"]
[Learning outcomes and connection]
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v
[25.1 What a studio is]
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[25.2 The brief]
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[25.3 Generating alternatives]
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v
[25.4 Weighted evaluation]
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v
[25.5 Presenting and responding to review]
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v
[25.6 Practical activity]
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v
[Chapter synthesis]
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v
[Worked example] --> [Exercise EX049]
Learning outcomes and connection
After this chapter you can (1) run a structured design studio from brief to reviewed concept; (2) generate and compare concept alternatives against weighted criteria; (3) present a concept with its assumptions, risks and verification plan to a critical review panel; and (4) respond to review findings constructively. It integrates Chapters 16–24 into the first complete design artefact and prepares Chapter 26.
25.1 What a studio is
A design studio is an iterative, critiqued design exercise. Teams receive a brief, produce concepts, present them to reviewers who challenge assumptions, and revise. Its value is the critique: designs improve fastest when someone competent tries to break them early. In this course, each studio produces a concept dossier: problem statement, requirements excerpt, alternatives, evaluation, selected concept, risk register, verification plan and open questions.
For TMRP, Studio I's dossier covers remote operation of all six pumping stations and the Fenwick works.
25.2 The brief
Studio I brief (synthetic): LRWA must secure remote operation of PS1–PS6 and the Fenwick works. Constraints: budget 250 k (Lab 16); PS1 and PS2 have legacy RTU-A units that cannot be replaced for three years; private LTE is the only economical link; one control room, staffed 24/7 with one operator at night; the hospital needs ≤ 4 h interruption. Deliver: two to four concepts, evaluation, selection and verification plan.
The night staffing constraint is the one that most shapes the concepts, because any design that needs someone to drive to a station for every change leaves a single operator unable to keep up across six sites.
25.3 Generating alternatives
Generate concepts that differ in principle, not detail: (A) carrier-encrypted LTE with central firewalling only; (B) IPsec tunnels from new RTUs, gateways for legacy; (C) application-layer authentication with gateways and strong local autonomy; (D) no remote control at all — monitoring only, with operators dispatched for every change. Including an extreme (D) clarifies what remote control is worth.
The four concepts differ in where authentication happens and whether remote control exists at all. Concept D's very low operability score in the evaluation shows why an extreme is worth including.
25.4 Weighted evaluation
Define criteria from requirements and constraints, weight them before scoring, score each concept with evidence, and test whether the ranking survives plausible weight changes (sensitivity). A weighted sum is a structured conversation, not an oracle.
| Criterion (weight) | A | B | C | D |
|---|---|---|---|---|
| Prevents forged commands, R1 (0.30) | 1 | 4 | 4 | 5 |
| Service during network loss, R4 (0.20) | 2 | 3 | 5 | 5 |
| Operability with one night operator (0.20) | 5 | 4 | 4 | 1 |
| Cost within 250 k (0.15) | 5 | 2 | 4 | 4 |
| Legacy compatibility (0.15) | 5 | 3 | 4 | 5 |
| Weighted score | 3.20 | 3.35 | 4.20 | 4.05 |
D scores close to C because it is very secure, but its operability score reflects that one night operator cannot drive to six sites; it fails the hospital need in practice. The panel's challenge to the team is to show that C's lead survives if operability is weighted at 0.10 and R1 at 0.40 (EX049).
25.5 Presenting and responding to review
Present: the problem in one sentence, constraints, alternatives, evaluation, selection, risks, and what you have not verified. Reviewers will attack assumptions; record each finding, respond (accept, reject with reason, defer with owner) and revise. A defensive team learns nothing; a team that accepts every comment has no design.
The panel findings in EX050 are typical for TMRP: the gateway as a single point of failure, local manual mode bypassing authentication, and missing key-management staffing costs. Each needs a logged response with an owner. The second can be answered with evidence that already exists, because the key switch, alarm and local log were recorded when the conflict between R4 and R1 was resolved.
25.6 Practical activity
Produce the concept dossier for the Studio I brief in no more than eight pages and hold a 20-minute review with two peers acting as panel.
Keep to eight pages so the panel can read it before the review. Present the four concepts in the weighted table, show the sensitivity check and state what has not been verified. Ask the peers to attack one assumption each, such as the cost estimate or the night operability score. Record their findings in a response log with accept, reject or defer and an owner, as EX050 asks, and revise the concept before submitting the dossier.
25.7 Common errors and limits
- Alternatives that are variations of one idea.
- Weights chosen after scoring.
- Scores without evidence.
- No sensitivity check.
- Treating review as a test to pass rather than information.
Studio I guards against these: its four concepts differ in principle, its weights were fixed before scoring, and EX049 tests whether concept C's lead survives other weights. The panel's challenge to concept D, which scores well on security but fails night operability, is the kind of finding a review should produce. Every score cites evidence.
Exercises — chapter 25
EX049 — Weight sensitivity. Objective: test the robustness of a selection. Inputs: the table in §25.4. Steps: recompute with weights (R1 0.40, network loss 0.20, operability 0.10, cost 0.15, legacy 0.15) and with (R1 0.20, network loss 0.20, operability 0.30, cost 0.15, legacy 0.15). Expected evidence: scores and conclusion. Rubric: 3 = correct arithmetic and an honest conclusion about when D overtakes C and what that implies; 2 = one arithmetic error; 1 = one scenario; 0 = none.
EX050 — Review response log. Objective: respond to critique. Inputs: three panel findings: "gateway is a single point of failure"; "local manual mode bypasses authentication"; "cost estimate ignores key management staffing". Steps: write a response log entry for each (accept/reject/defer, reason, change, owner). Expected evidence: log. Rubric: 3 = substantive responses with design changes where warranted (e.g., dual gateways or fail-to-local-automatic; key-switch and alarm; add operating cost line); 2 = one dismissive; 1 = accepts all without change; 0 = none.
Chapter synthesis
A studio turns knowledge into a design under critique. Generate genuinely different alternatives, including extremes; weight criteria before scoring and test sensitivity; present assumptions and unverified claims openly; and treat review findings as design information with recorded responses.
Continue studying — chapter 25 of 50
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