Loads: define them before you design anything
Loads come first. State them in plain terms and show where they act. Split them as static, variable, impact and environmental (temperature, moisture, corrosion, vibration). If motion is involved, include acceleration, braking and cornering. For structures, show the load path: where forces enter, how they flow, and where they leave. Combine loads into named cases (LC1, LC2, LC3…) and note the governing case for each critical part. Record factors of safety and any partial factors you apply. Use SI units throughout and keep units on every line.
Assumptions and data sources
Be open about what you assumed and why. Quote data sources for material properties, bearings, fasteners and bought-in parts (standard, grade, surface finish, heat treatment). If you scale from a catalogue graph, include the graph in the appendix and mark your pick. Where you estimate a value, give a range and show you tested the worst case.
Calculations that are easy to follow
Set out methods in small steps. Name variables, state units, and show substitutions before giving the final number. Round sensibly at the end, not in the middle. For repeated checks (e.g., shaft sizing, beam deflection, bolt shear), put the workings in a short spreadsheet and paste the key outputs in the report; put the full sheet in the appendix. If you use a solver or FEA, show the hand-calc that sets the expectation, then show mesh, boundary conditions and a simple convergence check. Link every result back to a requirement so the marker sees the pass/fail straight away.
Choosing materials and components
Explain each choice in one sentence tied to a requirement: “6082-T6 for the bracket due to strength-to-weight and machinability”, “A2-70 fasteners for corrosion resistance in a damp enclosure”. State standards (e.g., BS EN or ISO) and give the property that matters for that part: yield strength, hardness, bearing life, dielectric strength, IP rating, temperature class, duty rating. Note any treatment or finish that protects the part in service.
Drawings and models that tell the truth
Use clear orthographic views, a section where it saves words, and dimensions only where they control fit or function. Keep title blocks complete (part name, number, material, finish, units, scale, revision). Tolerances should match the real need—tight where it sets a fit, free where it doesn’t. If two parts must mate, put a fit note (e.g., H7/g6) rather than a vague “tight fit”. Add a simple exploded view to show how it goes together, and label critical items to match the BOM.
A Bill of Materials the marker can check in one glance
Put the BOM on one page if you can. Each line should have: item number, part number, description, material/spec, quantity, process/finish, and source (make/buy, supplier and part code if bought-in). Keep names short but exact. Match every item tag on the drawing to a BOM line. If there are variants or options, group them and explain in a note. If you replaced a part during development, show the superseded number in the revision history so the trail is clear.
Build, test and inspection plan
Explain how the design will be made and checked. Note key operations (cut, drill, turn, mill, print, bend, weld, assemble). State any jigs or fixtures. Give the critical inspections: which dimensions are checked, with what tool, and against which tolerance. For electronics, list functional tests; for structures, note proof loads and simple gauges. Tie each test back to a requirement and state a pass mark.
Compliance, safety and the quiet checks that gain marks
If a standard applies, name it and show the specific clause you meet. Add a short hazard review: point out pinch points, sharp edges, high temperatures, pressure, electrical shock, stored energy and handling risks. State the control: guard, warning, interlock, relief, isolation, PPE or procedure. Keep it practical and proportionate to the assignment.
Evaluation that satisfies LO4
Bring it back to the brief with numbers. Report the final mass, size, footprint, power draw, factor of safety, expected life, cost and build time. Compare to targets and discuss any shortfalls with reasons. Explain trade-offs you made, such as a slightly heavier bracket to cut machining cost, or a slower fan for lower noise. Add two or three improvements worth doing next and show their likely benefit. Close with a short note on sustainability or service: spare parts, recyclability, ease of disassembly, or energy use over life.
Referencing and appendices
Keep references tidy and consistent. Put datasheets, catalogue pages, raw calcs, solver logs and test notes in the appendix with page numbers. Any figure or table in the main report should have a source or a link to your appendix. This is simple to do and stops lost marks for traceability.
Common mistakes that cost marks
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Loads not stated or mixed units.
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Calculations with no link to a requirement.
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Drawings without tolerances, or a BOM that doesn’t match the tags.
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FEA with pretty pictures but no boundary conditions or hand check.
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No evaluation—just a result with no comment on fit to brief.
Quick pre-submission check
Read the brief aloud and point to the page that proves each requirement is met. If you cannot point to it in three seconds, add a label, a table or a short line to make it obvious. Check units and symbols are consistent from front to back. Make sure every part in a drawing appears in the BOM and vice versa. Confirm revisions match across the model, drawing and BOM.
