MA – L2 – Q26 – Standard Costing and Variance Analysis

Standard marginal production cost – Product AB

Direct materials (8 kilos at GH¢1.50 per kilo)
Direct labour (2 hours at GH¢4 per hour)
Variable production overhead (2 hours at GH¢1 per hour)
Standard marginal production cost

Tutorial note: This problem tests your understanding of the formulae for calculating variances. Here, you are given the actual costs and the variances, and have to work back to calculate the standard cost. The answer can be found by filling in the balancing figures for each variance calculation.

Workings
Materials price variance
150,000 kilos of materials did cost
Material price variance
150,000 kilos of materials should cost
(The variance is favourable, so the materials did cost less to buy than they should have cost.)

Materials usage variance
Materials usage variance in GH¢ = GH¢9,000 (A)
Standard price for materials = GH¢1.50
Materials usage variance in kilograms = 9,000 / 1.50 = 6,000 kilos (A) kilos
18,000 units of the product did use
Material usage variance in kilos
18,000 units of the product should use

Required:
Calculate the standard cost sheet for Product AB, including:

  1. Standard price for materials.
  2. Standard quantity of materials per unit.
  3. Standard time per unit for labour.
  4. Variable production overhead rate per hour.

Materials price variance

GH¢
150,000 kilos of materials did cost
Material price variance
150,000 kilos of materials should cost 225,000

(The variance is favourable, so the materials did cost less to buy than they should have cost.)
Therefore, the standard price for materials is GH¢225,000 / 150,000 kilograms = GH¢1.50 per kilo.

Materials usage variance

Materials usage variance in GH¢ GH¢9,000 (A)
Standard price for materials GH¢1.50
Materials usage variance in kilograms 9,000 / 1.50 = 6,000 kilos (A) kilos
18,000 units of the product did use 150,000
Material usage variance in kilos 6,000 (A)
18,000 units of the product should use 144,000

Therefore, the standard quantity of materials per unit of product = 144,000 kilos / 18,000 units = 8 kilos per unit.

Labour rate variance

GH¢
36,000 hours did cost
Labour rate variance 3,600 (F)
36,000 hours should cost 144,000

Therefore, the standard labour rate per hour = GH¢144,000 / 36,000 hours = GH¢4 per hour.

Labour efficiency variance

18,000 units should take 36,000 hours
They did take 36,000 hours
Variance in hours 0 hours
Standard labour rate per hour GH¢4
Labour efficiency variance in GH¢ GH¢0

Therefore, the standard time per unit of product = 36,000 hours / 18,000 units = 2 hours per unit.
This number of hours per unit also applies to variable production overheads.

Variable overhead expenditure variance

GH¢
32,000 hours did cost 38,000
Variable overhead expenditure variance 6,000
32,000 hours should cost 32,000

Therefore, the variable production overhead rate per hour = GH¢32,000 / 32,000 hours = GH¢1 per hour.

Standard marginal production cost – Product AB

Direct materials (8 kilos at GH¢1.50 per kilo) = GH¢12.00
Direct labour (2 hours at GH¢4 per hour) = GH¢8.00
Variable production overhead (2 hours at GH¢1 per hour) = GH¢2.00
Standard marginal production cost GH¢22.00