This workforce projection model provides a simplified estimate and should be interpreted cautiously due to several limitations inherent in its design. Its most significant weakness are estimating specialist and trainee ages (taken year of basic degree graduation and adding 25), not knowing when people will actually retire, assuming constant inputs, and neglects other potential attrition factors like voluntary departures or career changes, limiting its accuracy for complex, long-term strategic planning. Furthermore, the medical council workforce survey does not appear to publish non-retirement related attrition rates, hence the default values are best estimates based on reviewing the overseas data of non-surgical specialties.