The Lump Sum Savings insight determines the additional lump sum cash inflow that would be needed at any given point in the timeline (lump sum timing event) in order to prevent any future shortfalls from occurring thereafter in the plan.
When run, the lump sum inflow is used to pay expenses in that year and any remainder is deposited into a Needs Analysis Account and drawn upon in subsequent years of the plan.
Double click on a bar in the insight to view chart details (or click on Year View top right of the chart). The Needs Analysis Account is found on the Investments tab of this detailed view from the End Event year. The lump sum deposit to this account (in the End Event year) will be grown using the default growth rate on Investments. This growth rate is set from Dashboard view > Plan Settings > Inflation / Growth Rates > Investment Growth Rate. The default fees, deducted from this default growth rate, are also set in Plan Settings on the Fees & Taxation panel.