CMA Final Paper 13 common mistakes
CMA Final Paper 13 · Understand the traps and how to avoid them.
Treating all overhead as a single plant-wide pool and dividing by direct labour hours when the question supplies activity drivers (set-ups, machine hours, order handling), then reporting product costs that are wrong by a wide margin.
Candidates carry the absorption-costing habit from earlier papers and default to the familiar single rate without re-reading the data for multiple cost drivers. Time pressure reinforces the shortcut.
What to do instead
Before computing, list every cost pool and its stated driver in the question. Build a driver-rate table (pool cost divided by total driver quantity), then allocate by each product's driver usage. Sanity-check that total allocated cost equals total pool cost; if it does not, a driver was misapplied.
Ignoring opportunity cost, sunk cost, or committed fixed cost when a question asks for a relevant-cost decision (accept a special order, make or buy, discontinue a segment).
Candidates mechanically total all costs presented, treating every figure as relevant, and forget that allocated common fixed costs do not disappear when a segment is dropped.
What to do instead
Classify each cost as relevant (future, differential, avoidable) or irrelevant (sunk, committed, allocated common). For discontinue decisions, compare contribution margin lost against avoidable fixed costs saved, not against fully absorbed profit. State explicitly which costs you excluded and why.
Computing WACC with book values of debt and equity, or using the coupon rate on debt instead of the yield to maturity, and then discounting cash flows at that flawed rate.
Book figures are the easiest to pick from a balance sheet, and candidates confuse the historic coupon with the current market cost of debt. Tax-shield adjustment on debt is then also missed.
What to do instead
Use market values for weights; if only book values are given, say so and justify. Use the pre-tax yield to maturity for the cost of debt and multiply by (1 minus tax rate) for the after-tax cost. For equity, apply CAPM with a stated risk-free rate, beta, and market risk premium, and reconcile any figure to the inputs given.
Mixing nominal and real cash flows or mismatching the discount period (annual rate applied to mid-year or monthly flows) in an NPV or valuation question.
Questions often present real cash flows with a nominal discount rate, or vice versa, and candidates plug numbers into the formula without checking consistency. Timing conventions are skimmed.
What to do instead
State the convention up front: nominal flows with nominal rate, or real flows with real rate (Fisher relationship). Confirm whether flows occur at year-end or mid-year and adjust the discount exponent accordingly. Recompute the first period by hand to verify the exponent.
Describing a control weakness in general terms ("poor segregation of duties") without identifying the specific incompatible functions, the resulting exposure, and a compensating control.
Candidates memorise control labels but do not map them to the transaction cycle in the scenario. The answer reads as textbook recall rather than analysis of the given facts.
What to do instead
For each weakness, name the two incompatible duties (e.g., custody of cash and recording of receipts), state the fraud or error exposure and its financial statement effect, then propose a specific control (bank reconciliation by an independent person, dual authorisation above a threshold). Tie each point to a fact in the scenario.
Confusing inherent, control, and detection risk, or treating risk assessment as a single step rather than an ongoing process that responds to evidence.
The audit risk model is memorised as a formula but not applied to the scenario, so candidates assign risk levels without linking them to the nature of the entity, its environment, or prior findings.
What to do instead
Work through the model explicitly: inherent risk from the entity and its environment, control risk from the design and operation of controls, detection risk as the residual the auditor manages through procedures. Show how a higher assessed risk of material misstatement drives more substantive testing and a lower acceptable detection risk.
Resolving an ethical dilemma by listing the code of conduct's principles rather than applying a structured decision framework to the specific facts and identifying the stakeholders affected.
Candidates reproduce ethical theory and code headings, which scores poorly because the question tests judgement on a scenario, not recall of principles.
What to do instead
Use a fixed sequence: identify the facts and the ethical issue, list affected stakeholders and their interests, identify the relevant standards and any legal constraints, generate and evaluate alternatives against those standards, then recommend a course of action with escalation steps. Justify the recommendation by reference to the scenario facts.
Treating corporate governance as a compliance checklist and failing to distinguish the roles of board, audit committee, and management, or to identify conflicts of interest in a described board structure.
Governance codes vary by jurisdiction and candidates generalise from one framework. The scenario usually hides a structural flaw (e.g., CEO also chairs the board, or audit committee members lack independence) that goes unnoticed.
What to do instead
For each governance question, map the actors and their responsibilities, then test independence and competence: who appoints whom, who chairs, who has a financial relationship with the company. Flag any concentration of power and state the recommended structural remedy.
Choosing performance measures that reward the wrong behaviour, such as using residual income or ROI without adjusting for the investment base, or ignoring the balanced scorecard's cause-and-effect logic.
Candidates apply the formula but do not evaluate whether the measure aligns manager incentives with strategy, so they miss questions about goal congruence and suboptimisation.
What to do instead
For each measure, state what behaviour it encourages and whether that matches strategy. Where ROI or residual income is used, show the effect of a proposed investment on both the division's measure and the company's overall return, and explain the suboptimisation risk. For scorecards, link each perspective through an explicit cause-and-effect chain to the financial outcome.
Answering data analytics and digital transformation questions with generic benefits ("improves efficiency", "better decisions") instead of identifying the specific data, control, or governance issue raised by the scenario.
These topics are newer and candidates fall back on buzzwords. They also miss that analytics outputs need validation, and that automated controls require different testing from manual ones.
What to do instead
Name the data source, the analytical technique, and the decision it supports. Identify risks: data quality and completeness, model bias, access controls over the analytics environment, and reliance on automated controls without testing their logic. For transformation questions, address change management, skills, and the control implications of automation, not just the technology.