Sales receipts, and the year in which they are received, may fluctuate and there is a risk that forecast income will be lower than expected. Disposals might be affected by factors such as market conditions, the impact of COVID-19, the planning application process 14 Q 12; C&AG’s Report, paras 3.16 and 3.17 15 Qq 6, 46 and 90; C&AG’s Report, para 16 16 Qq 12 and 63 17 Q 6; C&AG’s Report, para 3.2 18 Q 56; C&AG’s Report, paras 1.11 to 1.14 19 Q 57 20 Q 51; C&AG’s Report, paras 12, 17, 3.4 and 3.5 Optimising the defence estate 11 and programme dependencies, such as the readiness of sites receiving displaced units. The Department told us that it could mitigate this by moving money between projects depending on the relative progress they have made.21