A Tuesday that crosses the county twice
Your engineers cover a patch of client sites: offices that can only be visited before 9am, schools that are only accessible in the holidays or after pupils leave, care homes that prefer mid-morning, industrial units with a gatehouse and a permit process. On top of monitoring, there are samples to take and deliver to the lab before its cut-off, and remedial jobs slotted in.
The planner builds each engineer's week in a diary, working from memory and a map. A school cancels, a care home has an outbreak and asks you to stay away, an urgent resample comes in. By Wednesday the plan has been rebuilt twice, and one engineer is driving past three sites on the way to a fourth, because those three are on someone else's list.
The constraints nobody wrote down
Routing looks like a map problem. In a water treatment business it is mostly a constraints problem, and the constraints live in people's heads.
- Access windows per site, and days when a site cannot be visited.
- Which engineers are trained or approved for particular tasks or client sites.
- Sampling visits that must reach the lab before its receiving cut-off.
- Tasks with a window, such as monthly checks that must fall within the calendar month.
- Site inductions or permits that take time on first arrival.
- Vehicle stock, such as whether the engineer has the right parts for a remedial job.
When the constraints are only known to one planner, holidays and sick days hit twice: once for the planner and again for every engineer they plan for.
Where the wasted miles go
Poor routes cost fuel and engineer time, which is the capacity you sell. They also make visits late in the month, which creates the missed-visit problem at month end. Samples that miss the lab cut-off may need retaking, which means another trip.
Engineers notice when they are sent back and forth across the patch, and it wears on morale in a trade where good people are hard to replace.
Route planning built around due work
- Each site holds its location, access windows, blocked dates, induction time and any engineer restrictions.
- The planner selects the period, and the system lists every task due, with its window and estimated time on site.
- A routing engine proposes a draft plan per engineer, grouping sites by area and access time, respecting skills and lab cut-offs, using a mapping service for real drive times.
- The planner moves, locks or removes visits by hand. Locked visits stay put when the plan is recalculated.
- When a site cancels, the planner asks for a re-plan of the affected days, and the system suggests where the visit could go.
- Engineers get their day on their phone in order, with directions, access notes and the task list for each site.
| Input | Example | Effect on the plan |
|---|---|---|
| Access window | Office, before 9am only | Scheduled first on the day |
| Blocked dates | School term time for certain areas | Moved to holidays or after hours |
| Skill | Cooling tower work | Only offered to approved engineers |
| Lab cut-off | Samples must arrive by early afternoon | Sampling visits early in the route |
| Locked visit | Client asked for Thursday | Stays fixed during re-planning |
The planner stays in charge. The system does the arithmetic of grouping and ordering, and the planner applies the judgement the data cannot capture.
A planner's week with a draft to start from
Monday morning starts with a proposed week rather than a blank diary. The planner spends their time on the exceptions: the site that rang, the engineer on leave, the urgent job. When someone else has to cover planning, the constraints are written into the system rather than stored in one person's memory.
Engineers see a day that makes geographic sense, with the access notes they used to learn by getting it wrong.
Checklist: is routing costing you?
- Only one person really knows how to plan the week.
- Engineers pass sites that are on someone else's list.
- Samples sometimes miss the lab cut-off because of route order.
- A single cancellation means rebuilding several engineers' days.
- Access windows and site restrictions are learned by experience, not written down.