Business Case Specialist

Addition Solutions; Greater London; Hybrid; GBP 86,000 - 117,000; Full time

Benefits offered by this job

Hybrid working in London

Job summary

Addition Solutions in London is seeking a Business Case Specialist to support high-profile public sector programmes across national security, immigration and digital infrastructure. You will shape investment proposals, secure funding and ensure value for money in line with Green Book guidance.

This role requires strong analytical and written communication skills, experience delivering SOC, OBC and FBC, and the ability to guide submissions through assurance gateways.

Qualifications

• Proven experience writing business cases across the Five Case Model dimensions.
• Strong knowledge of HM Treasury Green Book guidance and investment appraisal.
• Experience in cost-benefit analysis, optimism bias and risk adjustments.
• Ability to interpret complex programme budgets and delivery models.
• Excellent written communication and stakeholder influencing skills.
• Strong judgement to resolve conflicting evidence in decision-making.
• Active SC clearance is required.

Responsibilities

• Develop SOC, OBC and FBC to support funding decisions.
• Ensure submissions align with Green Book guidance and the Five Case Model.
• Critically review inputs for strategic alignment and value for money.
• Lead submissions through assurance gateways with departments and central government.
• Build relationships with financial, commercial and technical advisers.
• Present investment proposals to SROs and Treasury officials.
• Quantify socio-economic benefits and financial impacts.
• Identify and mitigate delivery risks affecting the financial model.
• Maintain accurate business cases throughout the lifecycle.

Skills

Five Case Model

Green Book guidance

Investment appraisal

Stakeholder management

Written communication

Analytical thinking

Active SC clearance

Cost-benefit analysis

Education

Better Business Cases Practitioner

APM certification

PRINCE2

Job description

Business Case Specialist

Location: London | Hybrid
Security Clearance: Active SC clearance required
Contract: £550 Day Rate

We’re partnering with a public sector organisation to appoint an experienced Business Case Specialist, supporting high-profile programmes across national security, immigration and digital infrastructure.

This is an excellent opportunity for a business case professional to shape investment proposals, secure funding and strategic approval, and ensure projects demonstrate clear value for money.

We’re particularly interested in candidates with experience developing business cases in line with HM Treasury Green Book guidance and the Five Case Model, alongside strong investment appraisal and stakeholder management skills.

The Opportunity

As Business Case Specialist, you’ll develop robust, evidence-based business cases that support funding decisions and strategic approval for complex programmes.

Working closely with financial, commercial and technical advisers, you’ll challenge project assumptions, assess costs and benefits, and translate complex information into compelling investment proposals.

This role requires someone who combines analytical rigour with clear communication, confidently guiding submissions through formal assurance and approval processes while maintaining business case accuracy throughout the project lifecycle.

Key Responsibilities

You’ll play a key role in supporting investment decisions by:

• Developing Strategic Outline Cases (SOC), Outline Business Cases (OBC) and Full Business Cases (FBC).
• Ensuring submissions align with HM Treasury Green Book guidance and the Five Case Model.
• Critically reviewing and challenging project inputs to ensure strategic alignment and value for money.
• Leading submissions through departmental and central government assurance gateways.
• Building strong working relationships with financial, commercial and technical advisers.
• Presenting complex investment proposals to Senior Responsible Owners (SROs) and Treasury officials.
• Quantifying socio-economic benefits, financial savings and non-monetary impacts.
• Identifying, monitoring and mitigating delivery risks that affect the financial model.
• Maintaining accurate and up-to-date business cases throughout the project lifecycle.

About You

You’ll be an experienced business case professional with strong analytical skills and the ability to turn complex financial and delivery information into clear, well-supported recommendations.

You will also have:

• Proven experience writing business cases across the Strategic, Economic, Commercial, Financial and Management dimensions of the Five Case Model.
• Strong knowledge of HM Treasury Green Book guidance and investment appraisal principles.
• An understanding of cost-benefit analysis, optimism bias and risk adjustments.
• The ability to interpret complex programme budgets and commercial delivery models.
• Strong judgement, with experience evaluating conflicting evidence to inform effective decisions.
• Excellent written communication skills, translating complex financial information into a compelling narrative.
• Strong stakeholder management and influencing skills.
• Active SC clearance.

Better Business Cases Practitioner, APM or PRINCE2 certification would be highly desirable.

Why Apply?

This is an opportunity to influence funding and strategic decisions for high-profile public sector programmes, helping ensure investment is supported by robust evidence and clear delivery plans.

You’ll benefit from:

• Hybrid working in London.
• The opportunity to support programmes across national security, immigration and digital infrastructure.
• Exposure to senior decision-makers and government assurance processes.
• Collaboration with financial, commercial and technical specialists.
• A role with direct influence on investment decisions, value for money and programme outcomes.

We are an equal opportunity employer and value diversity at our company. We do not discriminate on the basis of race, religion, colour, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.