8.6 Project sizing

Sizing criteria

The burning question remains: how much is enough? How big does a project plan have to be?

You should intuitively realize that not every project needs a human resources or finance plan – but does every project need a risk register too? What about a WBS?

One benchmark you can apply to determine which project documents need to be used and when, is the level of risk the project poses to the organization.

Remember this?

LOW RISK (1) MEDIUM RISK (3) HIGH RISK (5) SCORE
COST Less than 5% of our program budget Between 5-15% of our program budget Greater than 15% of our program budget 1/5
±10% confidence in the cost estimate ±25% confidence in the cost estimate Greater than 25% margin of error assumed in the cost estimate 3/5
Expected costs are fully allowed for in the annual budget or financed by the client Expected costs are partially allowed for in the annual budget or financed by the client Expected costs are neither allowed for in the annual budget nor externally financed 3/5
TIME The project can be delivered in less than 3 months The project can be delivered in less than 6 months The project will take more than 6 months to deliver 1/5
±10% confidence in the time estimate ±25% confidence in the time estimate Greater than 25% margin of error assumed in the time estimate 1/5
The project has no fixed deadline for delivery The project has a preferred (but not mandated) delivery window The project must be delivered on or by a fixed date 5/5
SCOPE We have successfully delivered this project five (5) or more times We have successfully delivered this project at least once before We have never successfully delivered a project like this 3/5
IMPACT Project delivery will noticeably impact one (1) department in our organization Project delivery will noticeably impact several departments in our organization Project delivery will noticeably impact most or all, including core service delivery 1/5
The project has no major precedent or subsequent dependencies The project has some major precedent or subsequent dependencies The project has several major precedent or subsequent dependencies 3/5
Project delivery presents no employee or public health and/or safety risks Employees/public may be at risk of minor injury or illness during project delivery Employees/public at risk of serious injury, illness or loss of life during project delivery 1/5
Project outcomes will fulfil one (1) strategic objective of our organization Project outcomes will fulfil several strategic objectives of our organization Project outcomes will fulfil most or all of the strategic objectives of our organization 1/5
STAKEHOLDERS The project can be fully delivered by our current staff Some project work will need to be shared with proven, existing partners The project will depend on collaboration with new and/or unknown partners 5/5
The project is only of internal interest to our organization There is likely to be some community interest in the project and/or its outcomes The project and/or its outcomes will be highly visible in the community 3/5
TOTAL RISK SCORE: 31/65 = 48%

We used this in our business case to assess the risk posed by each alternative to our organization.

The only change here is that we’ve added cost back in as a criterion – at the business case level, we assessed it independently.

So, how does it work here?

Theoretically at least, the lower the risk a project presents to an organization, the easier the project is to deliver. 

The easier a project is to deliver, the less planning and quality assurance processes are required!


Sizing guidelines

Here is a ready reckoner to project sizing and a framework for its application. 

It is important to note that, like everything else in project management, this a dynamic process.

In other words, at the end of your alternatives analysis, you may reclassify a project from medium to high risk.

Once planning is complete, you may decide that your medium-risk project is actually low-risk, and adjust your requirements accordingly.

Note, though, that none of these rules are inviolate, and the use of tools like the project sizing calculator will be ultimately subject to the unique contingencies of your projects and the preferences of your sponsoring organization.

Project initiation

Going right back to when the project is just an idea, a project deemed low risk may not need a full business case – a simple elevator pitch may be sufficient to justify its authorization. 

A high-risk project, on the other hand, may demand a fully developed business case that may run to hundreds of pages in report format.

Project planning

Every project will require at least a basic WBS, schedule and budget – these plans will necessarily become more detailed, however, the larger and riskier a project becomes. 

It may not be, though, that a project requires stakeholder and risk registers until the project passes into medium-risk territory, and detailed human resource and finance plans will only be the preserve of large, complex, and risky projects.

Project delivery

The risk-based sizing principle can also be continued into project delivery and close.

For example, whereas every project requires at least some form of status reporting, change might be managed in low-risk projects by a simple phone call or email exchange. 

Medium-risk projects, however, may demand formal change control processes and much more detailed status updates. 

High-risk projects might require all of this, as well as the maintenance of issues and change logs.

These are documents we will introduce in the next Module, so don’t worry too much if you don’t understand exactly what we are on about here!

Project close

Finally, at the end of every project, the manager and key staff should document their reflections on their own and the project’s performance. 

For projects that were flagged as medium risk, the organization should internally at least look to conduct a more formal review of the undertaking; on high-risk projects, they should commit to getting external, expert advice.

Importantly, your original project plan should allow for the time and cost of completing all these activities. 

There is no point in acknowledging the need to manage change logs or conduct an external review without allocating the resources necessary for their completion.

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