Project Explanation:
First u have to start with
1) You have to first explain about objective of the project and what is client expectations
2) You have to start where your involvement and responsibility of your job and limitations of job.
Add some points from post Project Architecture reply like offshore and onsite model and team structure. etc.,
Main objective of this project is we are providing a system with all the information regarding Sales / Transactions (sales if sales domain / transactions if bank domain or insurance domain) of entire organizations all over the country US / UK ( based on the client location US/UK/….). we will get the daily transaction data from all branches at the end of the day. We have to validate the transactions and implement the business logic based on the transactions type or transaction code. We have to load all historical data into data warehouse and once finished historical data. We have to load Delta Loads. Delta load means last 24 hrs transactions captured from the source system. In other words u can call it as Change Data Capture (CDC). This Delta loads are scheduled daily basis. Pick some points from What is Target Staging Area Post. Source to Staging mappings, staging to warehousing. based on your comfort level.
Each transaction contains Transaction code. based on the transaction code u can identify whether that transaction belongs to sales, purchase / car insurance, health insurance, /deposit , loan, payment ( u have to change the words based on the project.) etc., based on that code business logic will be change. we validate and calculate the measure and load to database.
Mapping explanation :
In Informatica mapping, we first look up all the transaction codes with code master table to identify the transaction type to implement the correct logic and filter the unnecessary transactions. because in an organization there are lot of transactions will be there but you have to consider only required transactions for your project. the transaction code exists in the code master table are only transactions u have to consider and other transactions load into one table called Wrap table and invalid records( transaction code missing, null,spaces) to error table. For each dimension table we are creating surrogate key and load into data-warehouse tables.
SCD2 Mapping:We are implementing SCD2 mapping for customer dimension or account dimension to keep history of the accounts or customers. We are using SCD2 Date method. before telling this you should know it clearly about this SCD2 method.