CORNELL · SYSEN 5930 · FALL 2023
Give a service idea a plan you can question.
Bon Appétit proposed a different approach to food and grocery delivery. I contributed to the team’s project management plan and wrote the cost-management chapter, bringing scope, budget and progress into the same discussion.
- Original work
- Team 8 · Bon Appétit
- My chapter
- Part 5 · Cost Management Plan
- This page’s experiment
- Created in 2026 · fictional values
TEAM CONCEPT / DELIVERY & LOCAL COLLECTION
From individual doorsteps to local delivery points.
The team proposed fixed delivery points near communities, followed by a short collection trip for customers. The aim was to improve routes and reduce loss during delivery, with drones or unmanned vehicles considered as possible extensions.
This was a course proposal for a service and product. The team’s planning material covered labour rates, task durations, a time-phased budget and a schedule baseline, which informed my cost-management section.
MY CHAPTER / START WITH SCOPE AND BUDGET
Ask whether the budget supports the proposed work.
Part 5 identifies me as the author of the cost management plan. I first asked whether the original budget could cover software optimisation, delivery facilities and potential unmanned delivery. I then explicitly introduced a hypothetical expanded budget to discuss costs across the proposed phases.
- 01
Start with scope
What work and resources sit behind fixed delivery points, local collection and possible unmanned delivery? How much of that scope is the budget meant to cover?
- 02
State the assumption
My cost chapter questions the fit between the original budget and proposed scope, then explicitly introduces a hypothetical expanded budget for design, development and prototyping.
- 03
Bring variance back to the work
Compare planned work, completed work and actual spend at the same reporting point, then identify what needs investigation.
The chapter brings cost and schedule variance and earned-value measures into monitoring, with fortnightly reports and quarterly reviews. Its amounts, thresholds and budget expansion were coursework assumptions. Looking back, I would keep the habit of checking scope before interpreting the numbers.
FROM THE ORIGINAL TO AN EXPERIMENT / SEPARATE THE THREE VALUES
Spending less and delivering to plan are separate questions.
Earned value management (EVM) values completed work using its agreed budget, then compares it with the plan and actual cost. If spending is below plan, the next question is whether the work was delivered efficiently or simply has not been done yet.
The experiment below uses new fictional values to explore that distinction. Planned value PV, earned value EV and actual cost AC refer to the same reporting point; the graphic is a snapshot.
TRY THE COMPARISON / A 2026 METHOD DEMONSTRATION
Spent, delivered, planned: three different numbers.
These new fictional scenarios use a total budget of 100 units and cumulative values at one reporting point. EV weights completed work by its agreed budget, rather than by how much was spent.
First ask: which work is behind plan?
Planned work: 60 units. Completed work at budget: 30. Actual cost: 25.
Earned value needs reliable completion evidence. These ratios do not translate directly into days ahead or behind.
- Cost variance CV
- 5
- Schedule variance SV
- -30
- Cost performance CPI
- 1.20
- Schedule performance SPI
- 0.50
EV − ACCompleted work compared with what it cost.
EV − PVProgress against planned work, in budget units, not days.
EV ÷ ACBudgeted work value delivered per unit spent.
EV ÷ PVCompleted work value relative to the plan at this point.
CV and SV: positive is favourable, negative unfavourable. CPI and SPI: above 1 is favourable, below 1 unfavourable. A zero denominator displays “—” because the ratio is undefined.
This demonstration compares one snapshot; actual cost can exceed the total budget. It does not forecast finish dates or final cost. Definitions & formulas: NSF EVM Gold Card (new tab) ↗
DECISION THEATRE / 02 · THE SEQUENCE BEFORE HANDOFF
Two days faster. Does delivery move too?
Seven activities turn a service idea into a handoff. Change the site or interface duration and inspect which chain determines the finish.
A fictional exercise authored in 2026, separate from the Bon Appétit schedule. Elapsed days start at zero. Dependencies are finish-to-start with no lag; resource limits are not modelled.
Prepare the service interface
Product and implementation · After: Agree scope and acceptance
Earliest start: day 2; finish: day 7. Total float: 0 days.
Total float is the room to move this activity without moving the current project finish. Float on connected activities cannot simply be added together.
Edit the seven durations
| Activity | After | Duration | Early start | Early finish | Late start | Late finish | Float |
|---|---|---|---|---|---|---|---|
| Agree scope and acceptancescope | — | 2 | 0 | 2 | 0 | 2 | 0 |
| Prepare the service interfaceinterface | scope | 5 | 2 | 7 | 2 | 7 | 0 |
| Prepare the collection pointsite | scope | 3 | 2 | 5 | 4 | 7 | 2 |
| Write operating instructionsbrief | scope | 4 | 2 | 6 | 5 | 9 | 3 |
| Run joint acceptance teststest | interface / site | 2 | 7 | 9 | 7 | 9 | 0 |
| Rehearse the handoffrehearse | test / brief | 2 | 9 | 11 | 9 | 11 | 0 |
| Confirm deliveryrelease | rehearse | 1 | 11 | 12 | 11 | 12 | 0 |
Method and three questions before handoff
Critical path method: a forward pass finds early dates, a backward pass finds late dates, and total float equals late start minus early start.
- Are you shortening the work that controls delivery, or work with existing float?
- Do independent activities still compete for the same person or equipment?
- After acceptance, does the next owner know who handles a failure?
KEEP THE CALL / LEAVE A VERSION OF THE DECISION
Keep the settings beside the reasoning.
Save the seven applied durations above. Crew count and priority order can be saved separately in the resource lab below. Unapplied inputs are excluded.
Restore a saved version of this tool (0)
Loading replaces this page’s settings and unapplied inputs. The original journal entry stays.
No saved versions of this tool yet.
RESOURCE LAB / THE SAME PLAN, FINITE CAPACITY
The tasks can overlap. Can the people?
Use the seven applied durations above. Each activity occupies one interchangeable crew for its full, uninterrupted duration. See whether limited capacity changes delivery, then adjust the scheduling order.
The current schedule finishes 0 days above the precedence-only bound. Changing the priority order can recover 0 days in this model.
Which activity gets a slot first?
Move activities up or down while keeping predecessors ahead. This is the order of reserving feasible intervals, not a rule that activities must start one by one.
- 01Agree scope and acceptance
- 02Prepare the service interface
- 03Prepare the collection point
- 04Write operating instructions
- 05Run joint acceptance tests
- 06Rehearse the handoff
- 07Confirm delivery
Occupied time and waiting
Solid bars show occupied time. Dashed segments show waiting for capacity after predecessors finish. The full table below gives every value.
One cell per day from day zero; each number is occupied crews, with capacity 2.
| Activity | Duration | Predecessors ready | Start | Finish | Capacity wait |
|---|---|---|---|---|---|
| Agree scope and acceptance | 2 | 0 | 0 | 2 | 0 |
| Prepare the service interface | 5 | 2 | 2 | 7 | 0 |
| Prepare the collection point | 3 | 2 | 2 | 5 | 0 |
| Write operating instructions | 4 | 2 | 5 | 9 | 3 |
| Run joint acceptance tests | 2 | 7 | 7 | 9 | 0 |
| Rehearse the handoff | 2 | 9 | 9 | 11 | 0 |
| Confirm delivery | 1 | 11 | 11 | 12 | 0 |
How is the shortest schedule found?
The solver checks all 8 precedence-valid priority orders. For each, it reserves the earliest continuous interval after predecessors finish and within crew capacity, then compares finish times. 4 orders reach the shortest finish; they need not produce distinct schedules.
This is a small exhaustive exercise: seven fixed-duration activities in whole days, no interruptions or holidays, and one interchangeable crew per activity. Skills, handoff costs and uncertainty in real projects require additional modelling.
Method reading: schedule generation schemes (new tab) ↗KEEP THE CALL / LEAVE A VERSION OF THE DECISION
Keep the settings beside the reasoning.
Save a version of the applied settings only when you choose. Unapplied inputs are excluded. Restore or compare saved versions from the local journal.
Restore a saved version of this tool (0)
Loading replaces this page’s settings and unapplied inputs. The original journal entry stays.
No saved versions of this tool yet.
LOOKING BACK IN 2026 / RETURN THE NUMBERS TO THE WORK
After finding a variance, ask who acts on it.
Reading the plan now, I would keep the measures beside the work breakdown: which deliverable is behind, why, who can fill the information gap, and when should it be reviewed again? Similar questions run through CUSD coordination and my later work on requirements and acceptance.
AFTER READING / THE CONVERSATION
What would you add?
Add an experience, ask a question or point out a correction. Both language editions share this article’s discussion.
Public comments are not open yet. Keep a draft on this device, or send your thoughts through the contact page.
Write a local draft
Only “Save on this device” stores the draft. Clear it on shared devices; it is not published automatically.
0 / 1600