First – the Budget.
It is quite simply the amount of money set aside or allocated to accomplish the project. Also, Budget is very different from Selling Price, which is what’s shown in the BOQ unit rate/amount. This BOQ value is loaded as the budgeted cost for the activity (using various methods). The term ‘budgeted cost’ is the default given by Primavera and is used as such by users. It is important to understand here that while Primavera makes use of this default term, (which can be edited), it is not “cost” as far as the Contractor is concerned. Rather, this is the cost for the Client (and selling for the Contractor). As long as this fundamental principle is understood and remembered it doesn’t matter by what default term Primavera denotes it. Having got past this, and for purposes of cost control, it should be appreciated that Primavera won’t itself know the actual cost automatically. In other words, Actual Cost figures have to be populated manually (unless using the Calculate Cost from Units, and Auto Compute Actuals options). So when one is updating the schedule with actual periodic data, actual cost information may also be incorporated if such analysis is required.
This still does not substitute for Budgeting, or for Project Budget. Sometimes people ask how to do budgeting with Primavera. To answer this, it must be clear what is meant by Budget and Budgeting. As said in the beginning of this post, budget is the money allocated for the project … this much is simple enough. Of this total budget, some predetermined/fixed portions may further be specified for different project components, tasks, or WBS. Some people may call this budget breakdown/sub-allocation as budgeting. Some may not, since for them Budget and Budgeting are the same thing. Indeed, they may never even be aware of using either of these terms in two consecutive sentences. Irrespective of all this fine print and general (dis)agreement, Budget (and related sums) is, to a degree, extrinsic to the schedule as opposed to distributed BOQ value which is intrinsic.
As mentioned above, since the budgetary sum(s) is relatively external (that is, the rate and state of progress have a much lesser bearing on budget than on, say, Earned Value, as also the budget being established prior to taking on projects), the depiction of the same in Primavera is also relatively external.
And now, finally, we come to the question’s answer. Depiction of the Budget is done using the Spending Plan option. It can be done from within the EPS at node level and project level and within the project at WBS level. The amount specified in EPS at project level adds up to the node (and nodes) through all constituent projects/sub-nodes. This can be observed in the tally section. It’s essentially meant to be a top down approach, i.e. specify budget (periodic basis) for the Project and work down to the WBS; for the EPS node, sub-node and the Project. The limitations are that (at present) graphical representation is not available and the spending plan is brought in from an external source, e.g. excel template and is not affected by the schedule’s behavior. Ditto for the expected benefits (inflow), which can be fine-tuned at a later stage, either in relation with the cash flow (S curve) or the actual costs.
Note: The views expressed are my own; some individuals may have a different standpoint, which is perfectly OK.