Big Rocks Planning, and why it's a great way to start prioritization
Big Rocks: A simple model for a complex challenge
Most organisations do not fail at strategy because they pick the wrong big bets.
They fail because they cannot decide where to focus.
Perhaps they try to land too many ambitious programmes.
Perhaps they forget to invest in less glamorous operational work.
Or perhaps they let small “business as usual” initiatives quietly overwhelm delivery teams.
Either way, Big Rocks planning is a powerful way to solve the problem — and to put you back in control of strategic delivery.
The Big Rocks model (a quick refresher)
Derived from Stephen Covey’s time management principle, the concept is deliberately simple.
You have a jar to fill. You can add:
- Big Rocks
- Pebbles
- Sand
If you start with the Big Rocks, everything else can fit around them.
If you start with the sand, it cannot.
The parallel to portfolio planning is hard to miss.
- Big Rocks are your key strategic initiatives. High visibility, high potential impact — but also cross‑team resourcing, big budget, and multi‑director buy‑in.
- Pebbles are important divisional or operational initiatives. Critical to their sponsors, but with less enterprise‑wide impact. Until something breaks.
- Sand is everything else: the small asks that usually make sense in isolation but collectively erode focus.
And the jar is your capacity.
It’s the reason you cannot do everything. And it’s why controlling what goes into the jar — and when — is one of the PMO’s most important responsibilities.
That is the real portfolio problem.
Not a lack of ideas.
Not a lack of ambition.
Not even, most of the time, a lack of process.
If this sounds like common sense, that’s because it is. And that accessibility is exactly what makes Big Rocks such a powerful planning heuristic. No trademarked methodology. No technical language to put people off.
So let’s look at five levers for making Big Rocks the foundation of your portfolio delivery capability.
1. Sand gets everywhere
The trouble with sand, as any beach‑goer knows, is that it gets everywhere.
But here’s the nuance: sand is not automatically bad. Some sand delivers quick wins, removes friction, improves service, and builds momentum.
The problem is not that sand exists.
The problem is when it is allowed to accumulate without discipline.
This is where many PMOs get caught out.
If the process for assessing small work is too heavy, people will route around it. Local backlogs form. Shadow portfolios emerge. And suddenly large chunks of time disappear into an ill‑defined “BAU” line.
A better answer is proportional rigour.
Lower‑level work should be assessed quickly and lightly — but still with enough structure to prevent waste and hidden backlog growth. And make sure your Sand is really Sand, and not a Big Rock in disguise.
Not one‑size‑fits‑all with more time spent reviewing than doing.
But not a free‑for‑all of “just one more thing” either.
2. The jar is not elastic
The jar represents delivery capacity.
That means people, bottlenecks, budget, time, and organisational attention. Which is exactly why prioritisation without capacity planning is meaningless.
If the jar is fixed, the real question is not what looks attractive in isolation — it’s what the organisation can actually deliver without overload.
While detailed capacity planning can get technical, the jar metaphor is refreshingly simple. You don’t negotiate with a jar. You don’t tell it to work harder. And you can’t fit everything in by pretending things are smaller than they are.
You decide what goes in.
You fill it intentionally.
And when it’s full, you stop until something comes out.
3. You can’t have all the Big Rocks
Most planning processes generate more Big Rocks than can realistically be delivered.
That makes selection — not ideation — the critical discipline linking strategy to portfolio management. But with AI making every proposal look fantastic, it's critical that proposals are scrutinised by the right people, applying a rigorous set of criteria to determine relative value.
By turning judgement into data you're half way to a robust cost-benefit ratio.
The other element is to understand the cost of the proposal, and for this you need the discipline of good forecasting, that provides a best feel idea for both resources and investment required to deliver the project.
At this point we can now answer a simple, but pivotal question:
Which Big Rocks actually fit in the jar — and which must wait?
This turns aspirational strategy into an achievable roadmap.
It also gives leadership what they value most: confidence in what is coming, and when.
And as a bonus for the PMO, adding this step into the planning process is a fantastic way to earn your seat at the table, as you change your role from being the blocker who explains why everything is late, to a key enabler in the execution of the company's strategy.
4. Keep space for Pebbles
Big Rocks planning can create an unhealthy fixation on high‑profile programmes with jazzy codenames and executive visibility.
But many initiatives with significant operational value also deserve space in your jar.
This is where a portfolio‑led approach matters.
Firstly, by grouping Pebbles into their own portfolios, you can apply criteria that reflect their true value. Technical debt, for example, may not excite executives — but it can quietly undermine everything that does.
Secondly, by explicitly allocating capacity to operational portfolios, you ring‑fence space for the work that keeps the organisation functioning.
And you give leadership another thing they want: control.
Do they want one more Big Rock — or five more Pebbles?
The choice should be theirs.
But the answer cannot be both.
After all, it all has to fit in the jar.
5. From insight to action
Of course, in reality it’s never quite this straightforward.
People debate the relative value of every stone.
Estimates shift as “T‑shirts” start looking uncomfortably tight, and you start to wonder if your Sand might actually be more of a Rock.
Then of course, the jar is actually ten teams, three budget lines, and a hiring freeze that shrinks capacity every time you burn out another Developer.
And then strategy changes in Q2.
That’s why we created TransparentChoice, an innovative way to take control of strategic planning.
We apply Decision Science to turn opinions into scores, and use AI to make jar‑filling a one‑second exercise. That means you stay in control — offering leadership clear, simple choices about how they want to use their capacity.
They can fill the jar however they choose.
They just can’t change the fact that there is a jar.
We know this is not a simple challenge, but it's one we've solved for clients before, so whether you're suffering from messy data, noisy politics, or a leadership group that's allergic to "no" we're here to help.