+ve

• Usually cheaper
• Implement at own pace
• Use and develop in-house skills
• Staff already 'up to speed'
• Retain knowledge in-house
• Often easier to get user buy-in
• Awareness of local cultural constraints and other internal barriers

+ve

• Often quicker
• Broader knowledge base
• More detached perspective
• Reduced need for internal training and development
• No internal staff constraints
• Independence may enhance buy-in and credibility
• Access to leading-edge concepts
• Knowledge of pitfalls
• Track record

-ve

• Longer time to accomplish, due to other pressures
• Potential resource drain
• Appropriate knowledge and skills may not be available: rarely an in-house core competence
• Constrained view of problem and potential solutions
• Too close to the problem
• May be less easy to find and sustain the necessary investment
• Conflicting demands may push towards short-term fix rather than long-term benefit

-ve

• May be expensive
• Risk of not retaining knowledge in-house
• Potential loss of control
• May offer 'pre-packed' solutions rather than problem- or opportunity-specific
• Lack of exclusivity and competitive edge if adopt 'standard' solutions
• Solution may generate unforeseen need for future additional cost
• Potential over-dependence on a third party
• May provide short-term fix rather than long-term benefit