Best Practice Table Creation for Multiple Customers, Weekly/Monthly Sales Data in Multiple Fields

Question

We have an homegrown Access database originally designed in 2000 that now has an SQL back-end.  The database has not yet been converted to a higher format such as Access 2007 since at least 2 users are still on Access 2003.  It is fine if suggestions
will only work with Access 2007 or higher.
I'm trying to determine if our database is the best place to do this or if we should look at another solution.  We have thousands of products each with a single identifier.  There are customers who provide us regular sales reporting for what was
sold in a given time period -- weekly, monthly, quarterly, yearly time periods being most important.  This reporting may or may not include all of our product identifiers.  The reporting is typically based on calendar-defined timing although we have
some customers who have their own calendars which may not align to a calendar month or calendar year so recording the time period can be helpful.
Each customer's sales report can contain anything from 1,000-20,000 rows of products for each report.  Each customer report is different and they typically have between 4-30 columns of data for each product; headers are consistently named.  The
product identifiers included may vary by customer and even within each report for a customer; the data in the product identifier row changes each week.  Headers include a wide variety of data such as overall on hand, overall on order, unsellable on hand,
returns, on hand information for each location or customer grouping, sell-through units information for each location or customer grouping for that given time period, sell-through dollars information for each location or customer grouping for that given time
period,  sell-through units information for each location or customer grouping for a cumulative time period (same thing for dollars), warehouse on hands, warehouse on orders, the customer's unique categorization of our product in their system, the customer's
current status code for that product, and so on.
Currently all of this data is stored in a multitude of Excel spreadsheets (by customer, division and time period).  Due to overall volume of information and number of Excel sheets, cross-referencing can take considerable time.  Is it possible to
set-up tables for our largest customers so I can create queries and pivot tables to more quickly look at sales-related information by category, by specific product(s), by partner, by specific products or categories across partners, by specific products or
categories across specific weeks/months/years, etc.  We do have a separate product table so only the product identifier or a junction table may be needed to pull in additional information from the product table with queries.  We do need to maintain
the sales reporting information indefinitely.
I welcome any suggestions, best practice or resources (books, web, etc).
Many thanks!

Answer 1

Currently all of this data is stored in a multitude of Excel spreadsheets (by customer, division and time period).  Due to overall volume of information and number of Excel sheets, cross-referencing can take considerable time.  Is it possible to
set-up tables .....
I assume you want to migrate to SQL Server.
Your best course of action is to hire a professional database designer for a short period like a month.
Once you have the database, you need to hire a professional DBA to move your current data from Access & Excel into the new SQL Server database.
Finally you have to hire an SSRS professional to design reports for your company.
It is also beneficial if the above professionals train your staff while building the new RDBMS.
Certain senior SQL Server professionals may be able to do all 3 functions in one person: db design, database administration/ETL & business intelligence development (reports).
Kalman Toth Database & OLAP Architect
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