1. A build process comprising: generating, and storing in a storage device, a plurality of data sets that define a product during respective phases of a lifecycle of the product and identify components of the product by respective unique keys each of which includes a component identifier and an instance identifier, the plurality of data sets including (a) an engineering bill of materials generated during a design phase and defining the product as designed, (b) a sales bill of materials generated during a manufacturing planning phase and defining the product as ordered, and (c) manufacturing bills of material generated during a manufacturing phase and defining the product at respective stages of completion; designing a new configuration of the product during an additional, reconfiguration phase of the respective phases of the lifecycle of the product, the new configuration of the product including a change to at least one component of the product as designed; generating, and including in the plurality of data sets stored in the storage device, a further bill of materials defining the new configuration of the product; and repeatedly by a processor accessing the plurality of data sets from the storage device throughout the respective phases of the lifecycle of the product, determining any differences in the components of the product between phases of the respective phases, including any differences caused by a phase of the respective phases being incomplete, one or more components being unavailable or discontinued, a change to one or more components, or an error in a data set of the plurality of data sets, determining any differences including comparing different data sets of the plurality of data sets to identify any differences in the components of the product identified therein based on the respective unique keys, comparing the different data sets including at least: comparing the engineering bill of materials and the sales bill of materials during the manufacturing planning phase to identify any differences in components of the product as designed and as ordered; comparing the sales bill of materials and the manufacturing bills of materials throughout the manufacturing phase to identify any differences in components of the product as ordered and at the respective stages of completion; and comparing the engineering bill of materials and the further bill of materials during the reconfiguration phase to identify any differences in components of the product as designed and in the new configuration; accessing a policy with criteria for acceptable differences, and including criteria or requirements for changes to the product as designed; determining, from the policy for any differences so identified, whether the differences meet the criteria and are thereby acceptable differences, or the differences are errors, including determining whether the new configuration of the product meets the criteria or requirements; and generating a visual presentation of a data set of the different data sets for display in a graphical user interface, the visual presentation including components of the product identified in the data set, and for the components in the visual presentation, match indicators to indicate no differences in the components between the data set and another of the different data sets, and difference indicators to indicate any differences in the components between the data set and the other of the different data sets, wherein the visual presentation further includes an indicator that indicates the different data sets are reconciled in an instance in which no differences in the components are identified or the differences are acceptable differences, or that the different data sets are not reconciled in an instance in which the differences include at least one error.