Projects need good data to appropriately track programme performance, but the underlying data which communicates progress can be poor. The Comptroller and Auditor General’s report refers to multiple estimates and numbers being in use within Departments and insufficient or out of date evidence supporting reporting.37 As we noted recently in our report on EU Exit, Departmental processes for publishing information can also be delayed, or inconsistent with other information presented by government.38 There can also be trade-offs to manage between commercial confidentiality and public transparency in reporting cost and schedule performance.39