In NicolasJBM/manacc: Functions to simulate exercises in management accounting, and templates for these questions

##############################################################################
# Packages
library(exams)
library(manacc)
library(tidyverse)
library(knitr)
library(kableExtra)
library(randomNames)


##############################################################################
# Initialization
question_id <- "EN00000038"
wdir <- getwd()
parameters <- teachR::param_quest(wdir, question_id, alttype = "mcq", altlevel = "3 Apply")
for (i in 1:length(parameters)) assign(names(parameters)[[i]], parameters[[i]])
options(xtable.comment = FALSE, xtable.floating = FALSE, xtable.timestamp = "")
set.seed(seed)


##############################################################################
# Preparation
basepar <- manacc::income_statements(basevol = 20000, profitable = c(TRUE))
company <- basepar$company[[1]]
product <- basepar$product[[1]]
singular <- basepar$singular[[1]]
plural <- basepar$plural[[1]]

person <- manacc::make_persons(1)
lastmonth <- lubridate::month(Sys.Date()-30, label = TRUE, abbr = FALSE)

basevar <- basepar %>%
  dplyr::select(vol, p, uvc, fc, oi) %>%
  t() %>%
  as.data.frame() %>%
  rename(Budget = V1) %>%
  dplyr::mutate(
    Assumption = c("Volume","Price","Unit variable cost","Fixed costs","Operating income"),
    Actual = purrr::map_dbl(Budget, manacc::wiggle, delta = 0.1)
  ) %>%
  select(Assumption, Budget, Actual)

basevar[5,"Actual"] <- basevar$Actual[[1]] * (basevar$Actual[[2]] - basevar$Actual[[3]]) - basevar$Actual[[4]]

sbv <- basevar[5,"Actual"] - basevar[5,"Budget"]
vv <- (basevar[1,"Actual"] - basevar[1,"Budget"]) * (basevar[2,"Budget"] - basevar[3,"Budget"])
fbv <- basevar[1,"Actual"] * ((basevar[2,"Actual"] - basevar[3,"Actual"]) - (basevar[2,"Budget"] - basevar[3,"Budget"])) - (basevar[4,"Actual"] - basevar[4,"Budget"])

sbv_fmt <- dplyr::case_when(sbv < 0 ~ paste0(writR::dbl(abs(sbv)), " (U)"), TRUE ~ paste0(writR::dbl(sbv), " (F)"))
vv_fmt <- dplyr::case_when(vv < 0 ~ paste0(writR::dbl(abs(vv)), " (U)"), TRUE ~ paste0(writR::dbl(vv), " (F)"))

fmt <- dplyr::case_when(fbv < 0 ~ " (U)", TRUE ~  " (F)")
wrong_fmt <- dplyr::case_when(fbv >= 0 ~ " (U)", TRUE ~  " (F)")

fbv_fmt <- paste0(writR::dbl(abs(fbv)), fmt)

wrong_fbv <- c(
  sbv + vv,
  sbv - (basevar[1,"Actual"] - basevar[1,"Budget"]) * (basevar[2,"Actual"] - basevar[3,"Actual"]),
  sbv - (basevar[1,"Actual"] - basevar[1,"Budget"]) * (basevar[2,"Actual"] - basevar[3,"Budget"]),
  sbv - (basevar[1,"Actual"] - basevar[1,"Budget"]) * (basevar[2,"Budget"] - basevar[3,"Actual"]),
  sbv + (basevar[1,"Actual"] - basevar[1,"Budget"]) * (basevar[2,"Actual"] - basevar[3,"Actual"]),
  sbv + (basevar[1,"Actual"] - basevar[1,"Budget"]) * (basevar[2,"Actual"] - basevar[3,"Budget"]),
  sbv + (basevar[1,"Actual"] - basevar[1,"Budget"]) * (basevar[2,"Budget"] - basevar[3,"Actual"])
)

wrong_fbv <- unique(setdiff(wrong_fbv, fbv))

wrong_fbv_fmt <- c(
  paste0(currencysymb, writR::dbl(abs(fbv)), wrong_fmt),
  paste0(currencysymb, writR::dbl(abs(wrong_fbv)), fmt),
  paste0(currencysymb, writR::dbl(abs(wrong_fbv)), wrong_fmt)
)

##############################################################################
# Answers

if (reqexpl != "" & exasolu == "exam" & type_table != "html") lines <- paste0("\\vspace{",7.5,"cm}") else lines <- rep(" \\ ", 2)
#lines <- rep("\\ ", 2)

questions <- c(paste0(currencysymb, fbv_fmt), sample(wrong_fbv_fmt, 4))

solutions <- c(TRUE, rep(FALSE,4))

explanations <- c(
  "",
  "",
  "",
  "",
  ""
)


##############################################################################
# Randomize order (do not edit)
alea <- sample(c(1, sample(2:length(questions), (alternatives-1))), alternatives)
questions <- questions[alea]
solutions <- solutions[alea]
explanations <- explanations[alea]

Question

r txt_question_id r company buys r product from foreign suppliers and sells them on the domestic market. In r lastmonth, the actual operating income was r writR::dbl(basevar[5,"Actual"]) instead of the r writR::dbl(basevar[5,"Budget"]) initially budgeted. r person$first_name[[1]] r person$last_name[[1]], the management accountant of the company, learned from the Chief Marketing Officer that sales people sold an actual volume of r writR::int(basevar[1,"Actual"]) r plural for a unit selling price of r currencysymb r writR::dbl(basevar[2,"Actual"]). This constrasts with the r writR::int(basevar[1,"Budget"]) r plural at a unit price of r currencysymb r writR::dbl(basevar[2,"Budget"]) initially budgeted. Unfortunately, r person$first_name[[1]] could not get from the purchasing manager the necessary information about the actual unit variable cost. r tools::toTitleCase(person$pronoun[[1]]) only has the budgeted unit variable cost of r writR::dbl(basevar[3,"Budget"]). Actual and budgeted fixed costs are also missing.
\ What was the flexible budget variance in r lastmonth? r reqexpl r points
\ Hint: use the relationship between static budget variance, volume variance and flexible budget variance.

if (reqexpl == "") exams::answerlist(questions, markup = "markdown") else writeLines(lines)

Solution

In this situation, you do not have enough information to compute directly the flexible budget variance. Indeed, you are missing the actual unit variable costs as well as both actual and budgeted fixed costs. However, you have enough information to compute the flexible budget variance by subtracting the volume variance from the static budget variance:

$$ \begin{aligned} \text{Static budget variance} & = \text{Actual operating income} - \text{Budgeted operating income} \ & = r writR::dbl(basevar[5,"Actual"]) - r writR::dbl(basevar[5,"Budget"]) \ & = r sbv_fmt \ \ \text{Volume variance} & = (Q_A - Q_B) \times UCM_B \ & = (r writR::int(basevar[1,"Actual"]) - r writR::int(basevar[1,"Budget"])) \times (r writR::dbl(basevar[2,"Budget"]) - r writR::dbl(basevar[3,"Budget"])) \ & = r vv_fmt \ \ \text{Flexible budget variance} & = \text{Static budget variance} - \text{Volume variance} \ & = r sbv_fmt - r vv_fmt \ & = r fbv_fmt \end{aligned} $$

Note: positive and negative variances should be penalized: variances should be absolute numbers with an indication about whether they are favorable (F) or unfavorable (U).

if (reqexpl == "") exams::answerlist(ifelse(solutions, "True", "False"), explanations, markup = "markdown") else writeLines(c("\\ ","\\ "))

Meta-information

extype: r extype exsolution: r exams::mchoice2string(solutions, single = TRUE) exname: r question_id

NicolasJBM/manacc documentation built on Jan. 16, 2020, 1:42 p.m.