Standard Costing and Variance Analysis

Weightage: Chapter 8 of ICAI's Paper 4 syllabus, roughly 14 marks. One of the three heaviest chapters in the paper, and the one the method chapter warns produces the most sign errors — write every formula in words before substituting numbers.

What standard costing does

A standard cost is a predetermined, carefully estimated cost of a unit of output, computed under specified, efficient operating conditions — the material that should be used, the price that should be paid for it, the labour time that should be taken, the rate that should be paid for it, and the overhead that should be incurred, all fixed in advance for a period.

Actual cost is then compared against this standard, and the difference — the variance — is decomposed into causes a manager can actually investigate and act on, rather than left as a single, uninformative total gap.

Favourable (F) — actual cost is less than standard, or actual revenue exceeds standard: a result better than planned. Adverse (A) — actual cost exceeds standard, or actual revenue is less than standard: a result worse than planned.

Material variances

Material Cost Variance (MCV) = Standard Cost of Actual Output − Actual Cost

$\text{MCV}=(\text{Standard Quantity for Actual Output}\times \text{Standard Price})-(\text{Actual Quantity}\times \text{Actual Price})$

This total splits into two sub-variances, each isolating one cause:

Material Price Variance (MPV) — isolates the effect of paying a different price than standard, holding quantity at the actual quantity purchased/used:

$\text{MPV}=(\text{Standard Price}-\text{Actual Price})\times \text{Actual Quantity}$

Material Usage Variance (MUV) — isolates the effect of using a different quantity than standard, holding price at the standard price throughout (so that price effects, already captured in MPV, are not double-counted here):

$\text{MUV}=(\text{Standard Quantity for Actual Output}-\text{Actual Quantity})\times \text{Standard Price}$

Check: MCV = MPV + MUV, always. If your two sub-variances do not sum back to the total variance, one has been computed wrong.

Where more than one material is used in a mix, the usage variance itself splits further into a Mix Variance (the effect of using a different proportion of materials than standard, at standard prices) and a Yield/Sub-Usage Variance (the effect of the total input quantity, and hence output yield, differing from standard, at standard mix proportions and standard prices) — a candidate should check whether a problem involves a single material (only MPV and MUV needed) or a mix of materials (MUV itself decomposes further).

Labour variances

The structure mirrors material variances exactly, with rate replacing price and time replacing quantity:

Labour Cost Variance (LCV) = Standard Cost of Actual Output − Actual Cost = (Standard Hours for Actual Output × Standard Rate) − (Actual Hours × Actual Rate).

Labour Rate Variance (LRV) = (Standard Rate − Actual Rate) × Actual Hours (paid).

Labour Efficiency Variance (LEV) = (Standard Hours for Actual Output − Actual Hours worked) × Standard Rate.

The idle time refinement. Where workers are paid for hours including idle time (time paid but not worked), Actual Hours paid and Actual Hours worked diverge, and this splits Labour Efficiency Variance further: an Idle Time Variance = Idle Hours × Standard Rate (always adverse, since idle time is definitionally unproductive) is separated out, leaving a genuine efficiency variance based only on hours actually worked.

$\text{LCV}=\text{LRV}+\text{LEV}+\text{Idle Time Variance (where applicable)}$

Where more than one grade of labour is used, LEV similarly splits into a Mix (Gang) Variance and a Yield Variance, mirroring the material mix/yield split.

Overhead variances

The most structurally complex family, because overhead itself splits into fixed and variable components that behave differently, and each has its own variance decomposition.

Variable Overhead Variances

Variable Overhead Cost Variance = (Standard Hours for Actual Output × Standard Variable Overhead Rate) − Actual Variable Overhead.

Splits into Expenditure Variance (actual rate versus standard rate, at actual hours) and Efficiency Variance (actual hours versus standard hours for actual output, at standard rate) — structurally identical to the labour rate/efficiency split, since variable overhead is assumed to move with the same activity base (usually labour or machine hours) as labour itself.

Fixed Overhead Variances

This is where the chapter's genuine complexity sits, because fixed overhead, by definition, does not vary with activity, yet it is still absorbed into output using a predetermined rate based on budgeted activity — so any gap between budgeted and actual activity produces a variance that has nothing to do with spending and everything to do with how efficiently budgeted capacity was actually used.

Fixed Overhead Cost (Total) Variance = Absorbed Fixed Overhead − Actual Fixed Overhead = (Standard Hours for Actual Output × Standard Fixed Overhead Rate) − Actual Fixed Overhead.

This splits into:

Expenditure Variance = Budgeted Fixed Overhead − Actual Fixed Overhead (purely a spending comparison, nothing to do with activity level at all).

Volume Variance = Absorbed Fixed Overhead − Budgeted Fixed Overhead = (Standard Hours for Actual Output − Budgeted Hours) × Standard Fixed Overhead Rate (isolates the effect of actual output differing from budgeted output, at the standard rate).

Volume Variance itself further splits into:

Efficiency Variance = (Standard Hours for Actual Output − Actual Hours Worked) × Standard Fixed Overhead Rate (the same efficiency comparison as labour, now valued at the fixed overhead rate).

Capacity Variance = (Actual Hours Worked − Budgeted Hours) × Standard Fixed Overhead Rate (isolates whether the plant was actually run for more or fewer hours than budgeted, regardless of how efficiently those hours were used).

$\text{Fixed Overhead Cost Variance}=\text{Expenditure Variance}+\text{Efficiency Variance}+\text{Capacity Variance}$

Reading the volume/capacity/efficiency distinction correctly is the single most valuable thing in this sub-chapter: Expenditure asks "did we spend what we budgeted?"; Capacity asks "did we run the plant for the hours we planned?"; Efficiency asks "when we did run it, did we produce output at the rate we expected per hour?" — three genuinely different managerial questions, each pointing to a different corrective action if adverse.

The discipline that prevents sign errors

Every variance formula above is built the same way: Standard (for what was actually achieved) minus Actual, with the "what was actually achieved" component held constant across the two figures being subtracted so that only one variable moves at a time. Writing this out in words — "standard cost of actual output minus actual cost," "standard hours for actual output minus actual hours, valued at standard rate" — before substituting numbers is exactly the discipline the method chapter identifies as the fix for sign errors, and it is worth applying without exception, every time, in this chapter above all others in the paper.