Hi @ewats,
Total Accumulated Cost
This column displays the total cost for this level and all underlying levels in the part's structure.
WIP at Aggregation Date
The cost of work in progress for the shop order, as calculated on the last aggregation date.
Actual Accumulated Costs Total
This value is shown in the Shop Orders Costs overview and comes from the aggregated shop order cost calculation.
Aggregate Shop Order Costs per Shop Order: This task is used to calculate the aggregated costs for shop orders to be displayed in the Shop Orders Costs window. All open shop orders in the given site will be processed. If the shop order costs have been calculated previously, the previous aggregation result is removed and new costs are calculated. For closed shop orders, the system investigates if the shop order costs need to be recalculated. Standard estimated and actual costs and work in progress values for each shop order are captured per shop order. The system logs when the last aggregation occurred. This timestamp can be found in the Last Aggregation Date field in the Shop Orders Costs window.
So, each 3 elements that you have mentioned represent different costs and having different values for those values it understandable. The values in the Shop Orders page depend on the date you run the aggregation job but in shop order cost actual tab represents the more real time values, no need to run the aggregation job.