Project Grade 11 Careers & CTE
Thessley Growers Co-op: A Season Irrigation Service Plan
A grade 11 careers project in which teams build a season preventive maintenance calendar, crew-hour budget, and cost model for a fictional irrigation cooperative.
Objectives
- Students will convert projected run-hours into a count of required services for twelve stations.
- Students will build a season calendar and crew-hour budget that fits a stated labor limit.
- Students will match each recurring task to the credential that allows a worker to perform it.
Vocabulary
Key words: preventive maintenance, run-hours, scope of practice, chemigation, variable frequency drive, service agreement
Teacher overview
Teams act as the service crew lead for a fictional farming cooperative and plan six months of preventive maintenance on twelve irrigation pump stations. The driving question is how a two-person crew keeps twelve stations running through a season without overtime and without exceeding the parts budget. The deliverables are a season calendar, a crew-hour budget, a scope-of-practice table, a cost model with a graph, and a presentation to the cooperative board. Two misconceptions are worth naming in the first session. Students schedule by the calendar out of habit, yet equipment service intervals are set by run-hours, so two stations a mile apart can need very different numbers of visits. Students also assume any crew member may do any task, when a backflow assembly test and work inside an energized electrical panel each require a credential the crew may not hold.
Project Brief
Driving question. What service plan keeps all twelve Thessley stations running from April through September, who is allowed to do each task, and what does the season cost?
The client. The board of the fictional Thessley Growers Cooperative, which owns the stations and contracts your crew to service them. The board meets once and expects a plan it can approve as written.
The system. Twelve pump stations draw from Velmore Creek and from two wells. Four of the stations inject liquid fertilizer into the irrigation line during the season.
Constraints. Each of these is firm.
| Constraint | Requirement |
|---|---|
| Labor | One crew of two technicians, 30 hours per week for the 26 weeks from April through September, with no overtime |
| Parts and outside services | A season budget of $14,000 |
| Filter service | Each station needs a filter service after every 250 run-hours |
| Backflow testing | Each station's assembly is tested once during the season by a certified tester |
| Electrical work | Any work inside an energized 480-volt panel must be done by a licensed electrician |
| Access | Stations 6 and 11 sit on leased ground and need 24 hours of notice before a visit |
Station data, created for this project. Run-hours are the cooperative's projection for the season.
| Station | Projected run-hours | Injects fertilizer |
|---|---|---|
| 1 | 1,200 | No |
| 2 | 900 | Yes |
| 3 | 400 | No |
| 4 | 1,500 | Yes |
| 5 | 750 | No |
| 6 | 250 | No |
| 7 | 1,100 | Yes |
| 8 | 620 | No |
| 9 | 1,800 | Yes |
| 10 | 300 | No |
| 11 | 950 | No |
| 12 | 500 | No |
Fictional price list and time standards.
| Item | Figure |
|---|---|
| Filter cartridge set, one service | $95 |
| Crew time for one filter service | 1.5 crew-hours |
| Grease and oil, one station for the season | $40 |
| Certified backflow tester visit, one assembly | $85 |
| Licensed electrician call, one visit | $320 |
| Pump seal kit | $410 |
| Monthly station inspection | 1 crew-hour per station |
What you turn in. A season service calendar, a crew-hour budget, a scope-of-practice table, a cost model with its graph, and a six-minute presentation with a one-page service agreement summary.
Milestones
- Session 1, service demand. Use the run-hours and the 250-hour interval to find how many filter services each station needs, then total them. Output: a service demand table for all twelve stations with the season total shown.
- Session 2, calendar and labor. Lay the filter services and the monthly inspections across the six months so no week exceeds the crew's 30 hours. Add the two stations that need advance notice. Output: a month-by-month calendar plus a crew-hour budget compared against the hours available for the season.
- Session 3, cost and credentials. Write an equation with two variables that gives the season cost from the number of filter services, then graph it with both axes labeled and scaled. Build a table listing at least eight recurring tasks, and for each one name who may perform it: a crew technician, a certified backflow tester, a licensed electrician, or a licensed pesticide applicator. Output: the equation, the graph, and the completed table.
- Session 4, the board meeting. Present the plan in six minutes and answer two questions from a panel playing the board. Output: the final plan packet and the one-page service agreement summary naming what your crew will and will not do.
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Rubric
| Criterion | Emerging | Developing | Proficient | Advanced |
|---|---|---|---|---|
| Service demand from run-hours | Services are scheduled by the calendar with no use of run-hours | Run-hours are used for some stations | Every station's service count is derived correctly from its run-hours and the stated interval | Counts are correct and the team explains what changes if a station's projection is wrong by twenty percent |
| Calendar and labor budget | No calendar, or the plan exceeds the crew's hours | A calendar exists but weekly hours are not checked | The calendar fits within the weekly hour limit and accounts for both access-restricted stations | The calendar fits the limit, holds reserve hours for breakdowns, and states how the reserve was sized |
| Cost model and graph | No equation, or cost is a single unexplained number | An equation is written but the variables are undefined or the graph is unlabeled | A two-variable equation is defined correctly and graphed with labeled, scaled axes | The model is correct, graphed, and used to answer a board question about what the plan costs at a different service count |
| Scope of practice | Tasks are listed with no one assigned | Tasks are assigned without regard to credentials | At least eight tasks are matched to the credential that allows the work | Matching is correct, and the team explains which tasks must be subcontracted and what that adds to the budget |
| Presentation and agreement | Runs past time and the agreement is missing | Presents the plan but the agreement does not state limits | Presents within time and the agreement states what the crew will and will not do | Presents within time, answers both questions with evidence from the plan, and states the conditions under which the agreement would need to be reopened |
Differentiation
Support
Give teams the service demand table already completed for the first four stations so the division pattern is modeled, and provide a blank calendar grid with the weeks already labeled. Supply the cost equation with the variables named and only the coefficients left blank. Allow the scope-of-practice table to be completed from a provided list of four credentials rather than from memory.
Extension
Have teams add a breakdown scenario to the plan. A seal fails at the busiest station in July, the repair needs a fictional seal kit and six crew-hours, and the station cannot be down more than two days. Ask them to show which planned work moves, what the change costs against the season budget, and whether the plan still fits the crew's hours.
ELL supports
Pre-teach "preventive maintenance," "run-hours," "chemigation," "scope of practice," and "service agreement" with a labeled photograph or drawing of a station showing pump, filter, injection point, and control panel. Provide a sentence frame for the agreement summary: "Our crew will ___ each month, and we will call a ___ for ___." Allow the presentation to be read from a script.
Extensions
Have teams find what their own state requires for a commercial pesticide applicator license and for chemigation equipment, since state departments of agriculture publish both, and add one paragraph to the agreement stating which of those requirements falls on the crew and which falls on the grower. A second option is to have teams convert the season calendar into a simple work-order form, with the fields a technician would fill in at each visit, then trade forms with another team and judge whether the fields would capture enough to schedule the next service.