Portfolio Toolkit

Control

Project Sizing Tool

Project Sizing Tool

A framework for tailoring governance and control to the size, complexity, and risk of each project.

Table of Contents

Project Sizing Tool

Projects come in all shapes and sizes and no two are the same. It therefore makes sense to tailor the amount of governance and control to the project so that it is appropriate to the complexity, risk, and investment being made.

The project sizing tool provides an objective, repeatable method for categorising projects and determining the right level of PMO oversight, reporting, and governance for each one.

Principle: Governance should be proportionate. Too little creates risk; too much creates bureaucracy. The sizing tool finds the right balance.

Why Size Projects?

Benefit Description
Proportionate governance Right level of oversight for the risk and investment
Consistent standards Objective criteria applied to all projects
Resource efficiency PMO effort focused where it adds most value
PM expectations Clear expectations for deliverables and reporting
Portfolio visibility Consistent categorisation for portfolio views

Sizing Criteria

Assessment Dimensions

Dimension Weight What It Measures
Financial value 25% Total investment (capital + revenue)
Complexity 20% Technical, organisational, and integration complexity
Risk 20% Delivery risk, business risk, reputational risk
Strategic importance 15% Alignment to strategic priorities
Organisational impact 10% Number of teams, users, or processes affected
Duration 10% Expected project duration

Scoring Guide

Financial Value

Score Budget Range
1 < £50k
2 £50k – £250k
3 £250k – £1m
4 £1m – £5m
5 > £5m

Complexity

Score Description
1 Single team, known technology, no integration
2 Two teams, familiar technology, limited integration
3 Multiple teams, some new technology, moderate integration
4 Cross-functional, new technology, significant integration
5 Enterprise-wide, cutting-edge technology, complex integration

Risk

Score Description
1 Low risk, proven approach, experienced team
2 Some uncertainty, manageable risks
3 Moderate risk, some unknowns, mitigation needed
4 High risk, significant unknowns, active management needed
5 Very high risk, novel approach, critical dependencies

Strategic Importance

Score Description
1 Business as usual maintenance
2 Supports a strategic objective indirectly
3 Directly supports a strategic objective
4 Critical to a strategic objective
5 Board-level strategic initiative

Organisational Impact

Score Description
1 Single team affected
2 Single department affected
3 Multiple departments affected
4 Division-wide impact
5 Organisation-wide impact

Duration

Score Duration
1 < 3 months
2 3 – 6 months
3 6 – 12 months
4 12 – 24 months
5 > 24 months

Calculating the Size

Weighted Score Calculation

Dimension Weight Score (1–5) Weighted Score
Financial value 0.25 ? Weight × Score
Complexity 0.20 ? Weight × Score
Risk 0.20 ? Weight × Score
Strategic importance 0.15 ? Weight × Score
Organisational impact 0.10 ? Weight × Score
Duration 0.10 ? Weight × Score
Total 1.00   Sum

Size Categories

Weighted Score Size Category Colour
1.0 – 1.9 Small Green
2.0 – 2.9 Medium Blue
3.0 – 3.9 Large Amber
4.0 – 5.0 Major Red

Governance by Size

Deliverables Required

Deliverable Small Medium Large Major
Project mandate Required Required Required Required
Business case Simplified Standard Detailed Detailed + independent review
Project plan High-level Standard Detailed Detailed + baselined
Risk register Simplified Standard Standard Standard + portfolio escalation
Comms plan Optional Recommended Required Required
Quality plan Optional Optional Required Required
Benefits plan Simplified Standard Detailed Detailed + tracking
Closure report Simplified Standard Detailed Detailed + lessons

Reporting Requirements

Requirement Small Medium Large Major
Frequency Monthly Fortnightly Weekly Weekly
Report type Exception only Highlight report Full status report Full report + dashboard
Audience Line manager PMO PMO + Programme Board Portfolio Board
RAG update Monthly Fortnightly Weekly Weekly
Financial reporting Quarterly Monthly Monthly Monthly + forecast

Governance Arrangements

Element Small Medium Large Major
Project board Not required Optional Required Required
Board frequency N/A Monthly Fortnightly Fortnightly
Sponsor engagement Monthly check-in Fortnightly Weekly Weekly
Gate reviews Start + Close Start, Mid, Close All gates All gates + independent
PMO oversight Light touch Standard Active Embedded PMO support
Change control PM authority PM + PMO Project board Portfolio board

PMO Support Level

Support Small Medium Large Major
Planning support Templates only Templates + guidance Active planning support Dedicated planner
Risk support Templates only Quarterly review Monthly review Continuous support
Financial support Quarterly reconciliation Monthly reconciliation Monthly + forecast Continuous tracking
Assurance Self-assessment Annual healthcheck Quarterly healthcheck Monthly healthcheck

Sizing Examples

Example 1: Office Relocation

Dimension Score Rationale
Financial value 2 £150k budget
Complexity 2 Familiar activity, limited technology
Risk 2 Some logistics risk, manageable
Strategic importance 1 Operational, not strategic
Organisational impact 3 Multiple departments affected
Duration 2 4 months
Weighted total 2.0 Medium

Example 2: ERP Implementation

Dimension Score Rationale
Financial value 5 £8m budget
Complexity 5 Enterprise-wide, complex integration
Risk 4 Significant unknowns, vendor dependency
Strategic importance 5 Board-level strategic initiative
Organisational impact 5 Organisation-wide process change
Duration 5 30-month programme
Weighted total 4.8 Major

When to Re-Size

Projects should be re-sized when material changes occur:

Trigger Action
Budget increase >25% Re-assess financial value score
Scope change Re-assess complexity and organisational impact
Risk escalation Re-assess risk score
Duration extension >3 months Re-assess duration score
Strategic priority change Re-assess strategic importance
New size category Update governance and reporting requirements

Project Sizing Checklist

  • Sizing criteria understood by all PMs?
  • All active projects sized and categorised?
  • Governance requirements communicated to PMs?
  • PMO support levels aligned to project sizes?
  • Sizing reviewed when material changes occur?
  • Sizing tool calibrated annually against actual outcomes?
Last updated: 19 March 2026