Does the plan fit the team?

What a Gantt chart does not show

A bar on a Gantt chart has a start and an end. It does not say how many artists the task needs, and nothing under the bars says how many artists you have that month. A chart can be fully consistent — every dependency pointing forward, every task inside its milestone — and still require more people than the studio employs.

To check whether the plan fits, you need three numbers in the same unit: how much work there is, how many working days there are, and how many people you have on each of those days.

Use person-days, not hours

A task estimated at 30 hours takes four working days in practice: two meetings, a broken build, and it ends on Thursday of the following week. Over a nine-month production the hour-level detail adds noise without adding accuracy.

A day is the smallest unit a person can commit to: somebody worked on this on Tuesday, or they did not. Person-days also make the two sides of the calculation directly comparable: one person on the project for one week is 5 person-days of capacity, and a task estimated at 5 person-days is one person for one week.

Three numbers per discipline

Pick the window you will be asked about: a milestone, a quarter, or the time between two gates. For each discipline in that window, get three numbers.

1. Demand. Add up the estimates of every task in the window that needs this discipline, in person-days. A task that needs an artist and a programmer counts once for each.
2. Working days. Calendar days in the window minus weekends and holidays. Thirteen weeks is 65 working days, not 91.
3. Capacity. For each working day, count the people of this discipline who are on the project that day. Add the days up. Three artists for the whole window is 195 artist-days. Three artists where the third joins in week 7 is 65 + 65 + 35 = 165.

Then subtract: capacity minus demand, per discipline, per window. A negative result is a shortfall. Divide it by the working days to get the shortfall in people: “we are 0.7 of an artist short in milestone 3.”

Example

Milestone 3 is thirteen weeks: 65 working days. The art tasks in it add up to 240 artist-days. The roster has three artists, but the third starts in week 5, so capacity is 65 + 65 + 45 = 175 artist-days. Shortfall: 65 artist-days, which is one full artist for the whole milestone.

There are three ways to close a shortfall. Write down all three before the meeting, with what each one costs:

• Cut 65 artist-days of scope from the milestone. Name the tasks, and check what depends on them.
• Add capacity — hire, borrow from another project, or contract — and write down the date from which the new person actually counts.
• Move the gate by the number of weeks the shortfall needs, and follow every dependency that crosses the gate to see what else moves.

Two ways to count load

Effort. Spread each task's person-days evenly across the days it covers, then add them up per day. This is the calculation above. It tells you whether the total work fits the total capacity.

Concurrency. Ignore estimates and count heads: on a given day, how many tasks that need an artist are running? If four art tasks are open on the same Tuesday and there are three artists, one person is on two tasks, whatever the estimates say.

A plan can pass the effort check and fail the concurrency check — the total fits, but everything was scheduled to start on the same Monday. Run both.

Capacity has start and end dates

A roster written as “six engineers” is not capacity. Six engineers from January, one leaving in April and two joining in July is capacity. Write every person with a first day and a last day. Write open seats too, with the planned start date; “Artist 4, from 3 November” is a real row, and its date is the one that will slip.

The strictest check: assign everything

Totals can hide problems. The strictest check is to assign every task in the window to a named person who is on the project and free for the whole task, with nobody on two tasks at once. Whatever cannot be assigned is the part of the plan that exceeds the team, listed task by task.

Run this check again after every change: dates moved, somebody left, a milestone was split. The result from January is not valid in March.

Doing it in a spreadsheet

Columns are weeks, rows are disciplines, one sheet for demand, one for capacity, a third that subtracts. It works on the day you build it.

It stops working for three reasons. Dependencies are not in the sheet, so moving one task does not move the tasks behind it. The roster is a number per row rather than people with dates, so a delayed hire is fourteen cells to edit by hand. And there are several copies, and nobody knows which one the director has.

How Capaxima does it

Capaxima runs this calculation continuously. The roster holds people with a start and an end date. Tasks have estimates in person-days and the disciplines they need. Under the Gantt, a line per discipline shows demand against capacity for every day, in either reading — effort or concurrency — and turns red on the days where demand is higher. Automatic assignment runs the “assign everything” check and leaves in the backlog what nobody can take. Move a gate, remove a person or split a milestone, and the line updates in the same undo step.

It is a Windows desktop app, currently in beta. What it is and what it does not do · Request the beta.

Checklist before the meeting

• Every task in the window has a discipline and an estimate in person-days. Tasks without an estimate are counted as unknown, not as zero.
• Working days exclude the holidays you already know about.
• Every person on the roster has a start date; every open seat has a planned one.
• Capacity minus demand, per discipline, with the shortfall in people.
• The concurrency check: is there a day that needs more people than exist?
• Three ways to close each shortfall, with the cost of each.
• The list of tasks that cannot be assigned to anyone.