What the Army publishes about planning exercises
The British Army's public Officer Assessment page describes planning exercises at AOSB Briefing and Main Board. The Main Board description includes written work, group discussion and a plan developed from aims, factors, options and a chosen approach. Because these are publicly explained reasoning skills, candidates can practise them independently without reproducing the Board's actual material.
Start with the stage named in your own invitation. Briefing and Main Board are different, and some professionally qualified officer routes follow a separate structure. Project Selection's lab is intentionally not an AOSB simulation or predictor of an assessor's judgement.
Separate the objective from your preferred solution
Good reasoning begins with identifying the objective. Ask what must happen, by when, using which resources, and what cannot be changed. Make a short list of hard constraints and distinguish those from assumptions. If you start calculating before understanding the objective, a precise answer to the wrong question is still wrong.
In our original fictional community-aid exercise, the relevant constraints include a vehicle's carrying capacity, travel distance and loading time. A plan that ignores any one of those facts is not feasible, however persuasive its narrative sounds.
Make speed, distance, time and capacity explicit
A robust calculation shows the inputs and units. Convert travel time using distance divided by speed, multiplied by 60 to obtain minutes. Round a number of journeys or supervisors up only where the task actually requires whole units. A problem involving 42 boxes and capacity for 14 needs three complete loads, before adding the time taken to load or travel.
Review your answer in the context of the full plan. If 18 minutes of travel and 6 minutes of loading are required per trip, the correct combined duration for three trips is 72 minutes. Those numbers come from an invented teaching example, not Army selection material.
Compare options and communicate a defensible plan
State at least two feasible approaches, explain each one's principal advantage and weakness, then choose one using the objective and constraints. Identify the biggest assumption that could invalidate your choice and a sensible fallback. This format helps others assess whether they understand your recommendation.
Explaining why an option is inferior is more valuable than simply declaring the quickest route. Short, specific justifications are also easier to check and improve than paragraphs containing several unsupported claims.
What free practice can and cannot achieve
Our interactive AOSB planning lab provides original civilian scenarios and checks arithmetic, but does not pretend to judge leadership, teamwork, verbal communication or the quality of an individual's written plan. All working stays on the device and there is no official scoring conversion.
Use the Army's own assessment guidance first. If considering specialist coaching, verify who delivers it, their actual qualifications, how feedback is provided and whether the offer adds anything beyond free official material. Project Selection is not selling a verified coaching programme at present.
Try a relevant calculator or general practice exercise when it helps clarify this topic. No account, payment or official recruitment score is involved.
- Try 20 original planning exercises ↗
Independent civilian scenarios with worked maths, not Army-issued tests.
These related independent guides explore other stages of the same pathway.
- AOSB Briefing vs Main Board: Army Officer Preparation by Stage
- AOSB Communication Practice: Clear Arguments and Group Decisions
- AOSB Interview & Five-Minute Lecturette: Honest Preparation
- AOSB Preparation: Briefing vs Main Board, Fitness and Assessment
- Army Officer Bleep Test 7.10: Fitness Standards Explained
When an official benchmark for your exact role and stage is available, the free fitness comparison explains one numerical result. It is not an overall selection prediction.
Open the free comparison ↗Review the original page, especially before acting on dates, assessment stages or specific physical standards.
https://jobs.army.mod.uk/how-to-join/army-assessment/officer/
Public references examined in October 2026. This article is independent and may not reflect a later official change.