R/pmevR6.R

In pmev: Calculates Earned Value for a Project Schedule

#' Get linearly scaled variable based on optimal bins
#'
#' Finds outliers and then bands between 0 and 1 on optimal bins of
#' non-outlier data
#'
#' @param start Start Date of activity
#' @param end End Date of activity
#' @param progress Proportion between 0 and 1 representing percentage completed
#' for each activity (1 = 100% complete)
#' @param planned_cost The planned costs of each activity
#' @param project_value The total value of the project
#' @param cost_to_date The total amount spent on the project to date
#' @param date Character date "YYYY-MM-DD". Defaults to today.
#'
#' @examples
#' data(project)
#' tmp <- ev$new(start = project$start,
#'                        end = project$end,
#'                        progress = project$progress,
#'                        planned_cost = project$planned_cost,
#'                        project_value = 150000,
#'                        cost_to_date = 10000,
#'                        date = "2024-07-03")
#' plot(tmp)
#'
#' @importFrom ggplot2 ggplot geom_line theme scale_y_continuous labs
#' geom_vline annotate aes sec_axis theme_bw
#' @importFrom scales dollar percent label_percent
#' @importFrom lubridate today days
#' @importFrom vdiffr expect_doppelganger
#'
#' @export
#'

# https://www.projectengineer.net/the-earned-value-formulas/

ev <- R6::R6Class("ev",
  lock_objects = FALSE,
  public = list(
    #' @field planned_value (`numeric()`)\cr
    #'   Planned value schedule
    planned_value = NULL,
    #' @field earned_value (`numeric()`)\cr
    #'   Earned value calculations
    #' @return A new `ev` object.
    earned_value = NULL,
    initialize = function(start,
                          end,
                          progress,
                          planned_cost,
                          project_value,
                          cost_to_date,
                          date = today()) {
      tmp <- earned_value(start,
                          end,
                          progress,
                          planned_cost,
                          project_value,
                          cost_to_date,
                          date)
      self$planned_value <- tmp$pv
      self$earned_value <- tmp$ev
    },
    #' @description Plots the planned and earned values
    plot = function() {
      date_today <- as.Date(self$earned_value$date)
      pv <- data.frame(date = self$planned_value$end,
                       type = "Planned Value",
                       value =
                         self$planned_value$planned_value)
      ev <- pv[1, ] |> mutate(type = "Earned Value") |>
        rbind(data.frame(date = self$earned_value$date,
                         type = "Earned Value",
                         value = self$earned_value$earned_value))

      ac <- pv[1, ] |> mutate(type = "Actual Cost") |>
        rbind(data.frame(date = self$earned_value$date,
                         type = "Actual Cost",
                         value = self$earned_value$actual_cost))

      ev <- pv |> rbind(ev) |> rbind(ac)
      p <- ggplot(ev, aes(date, value, colour = type)) +
        geom_line(linewidth = 1.5) +
        scale_y_continuous(labels = dollar,
                           name = "Total Value",
                           sec.axis = sec_axis(~ . / max(pv$value),
                                               labels = label_percent())) +
        labs(colour = "",
             title = "Earned Value Chart",
             x = "") + theme_bw() +
        theme(legend.position = "inside",
              legend.position.inside = c(0.8, 0.2)) +
        geom_vline(xintercept = as.numeric(date_today),
                   linetype = "dashed",
                   color = "cornflowerblue") +
        annotate("text",
                 x = date_today + days(1),
                 y = max(ev$value),
                 label = "Today",
                 hjust = 0,
                 vjust = 1.5,
                 color = "cornflowerblue")
      return(p)
    }
  )
)