If ( t_ij < t_now ), the skill is . If between ( t_now ) and ( t_now + \delta ), it is critical . Otherwise valid . 2.3 Multi-dimensional expiry risk The aggregate skill expiry risk for a team/department is:
: Excel + email reminders → 23% of nurses had at least one expired skill at random audit. multi skill expiry date check
[ \textMSEDC(e_i) = s_j \in S_i \mid t_ij < t_now + \delta ] If ( t_ij < t_now ), the skill is