Some of it depends on the data. Dimensional might be better treated differently than a summable field.

For summable fields, you could have for example, line number, order number, current record flag, effectivity date (date of change), revision number, etc.

Say the value starts at 4 units, then is changed to 2 units.

Rev 1 shows 4 units, rev 2 shows -4 units, rev 3 (current record) shows 2 units.

Showing all records, you can see the progression, but summing still shows 2 units, the current value.

Not real elegant, but is one way of keeping the math right while showing changes in a verticle fashion.

Another thing that can become a factor - if you are tracking order lines as they come in, then they change over time, especially if they go through statuses and lines ship partially, change, then create new lines / sublines.

Looks like you have a couple of ideas, and something to read. Then run a couple examples by your users. Be sure to cover both fields you can aggregate, and other customer details that might be subject to change.

There are a few different ways of tracking changes, each with some pluses and minuses.