Redistribute the routes of a schedule over teams and days with constraints

schedule_fieldwork() hands the routes of each base to its teams with a simple rule (longest route first, one route per team-day). This function solves that distribution exactly as a small integer programme, through the highs package (in Suggests), which allows the constraints of real field work: teams unavailable on some days, routes fixed to a team or a day, routes that must precede others, a daily limit per team that lets two short routes share one team-day. The objective finishes as early as possible: it minimises the last working day of the schedule and, among schedules with the same end, the sum of the days on which routes are done.

Usage

schedule_calendar(
  schedule,
  availability = NULL,
  fixed = NULL,
  before = NULL,
  daily_limit = NULL,
  time_limit = 10
)

Arguments

schedule

A fieldopt_schedule from schedule_fieldwork().

availability

Optional data frame with columns team, day and available (logical): the team-days that are not listed are available. Team names are those of the calendar ("base-1", "base-2", ...).

fixed

Optional data frame with columns base, route and team and/or day: routes that must go to that team and/or that day.

before

Optional data frame with columns base, route, base_after and route_after: the first route must be done on an earlier day than the second.

daily_limit

Maximum duration of a team-day (in the unit of the travel matrix); the routes already respect the max_length of the schedule, so this is only useful to let several short routes share a day. NULL keeps one route per team-day.

time_limit

Seconds allowed to the solver.

Value

The schedule with its calendar, summary and fits recomputed, plus solver ("highs"), objective and status. An error when no calendar satisfies the constraints within days.

Examples

set.seed(5)
pts <- data.frame(
  unit = c("base1", "base2", paste0("s", 1:30)),
  x = c(2, 8, runif(30, 0, 10)), y = c(2, 8, runif(30, 0, 10))
)
m <- travel_matrix(pts, method = "euclidean")
sch <- schedule_fieldwork(m,
  units = paste0("s", 1:30), teams = c(base1 = 2, base2 = 1),
  days = 5, max_stops = 4, iterations = 30
)
if (requireNamespace("highs", quietly = TRUE)) {
  off <- data.frame(team = "base1-1", day = 1, available = FALSE)
  schedule_calendar(sch, availability = off)
}
#> 
#> ── Field schedule ──────────────────────────────────────────────────────────────
#> 30 units, 2 bases, 3 teams, 5 days available: the work fits.
#> "base1": 12 units, 2 teams, 3 routes, 2 of 5 days.
#> "base2": 18 units, 1 team, 5 routes, 5 of 5 days.