Input Output Descriptions

The I/O Descriptions below describe the dataflows that cross the boundary of the current physical business system for Acme Fashion Supplies.

As these are based on the top-level current physcal dfd, when it is decomposed and a better understanding gained, these descriptions will be updated and, no doubt, added to.

A useful cross check you can carry out is to make sure that each of the data items you identify in the descriptions appears in the entity descriptions of the logical data model

You'll also use these io descriptions later in helping to identify events.

Ref	From	To	Volumes	Description
IO1	Sell Product and Take Orders	Customer Master File	Orders, see IO6, Returns, see IO10, Dispatch Notes, approx 5-10 per week.	Orders and Returns. The top copy of the sales order is filed on raising. Yesterday's returns notes (received from the stock room) are filed here. Dispatch notes for any back orders are also files when fully supplied.
IO2	Sell Product and Take Orders	Accounts	Daily, at the end of the day	Sales and Returns Report. The details of today's sales and yesterday's returns. This includes, for each customer, name of order-taker, customer account number, value of sales, value of any items put on back order, value of items returned (discounting the value of damaged goods)
IO3	Accounts	Sell Product and Take Orders	A slow, steady 3 to 5 per week. Can be a few tens per week during an advertising campaign.	New Customer Details. Contains customer account number, company / outlet name, name of sales contact and email address (if provided), address, credit limit. If the customer included an order with their application, this is included, too.
IO4	Accounts	Sell Product and Take Orders	Daily, first thing in the morning.	Credit Limits. This is a list, sorted by company name, of customers nearing their credit limit. Each list entry consists of a customer account number, name, credit limit and account balance.
IO5	Sell Product and Take Orders	Customer	At most 1 or 2 per month.	E-Mailshot. Customer email address. The body of the message includes details of special offers and promotions; coordinated with marketing and used to shift slow moving stock.
IO6	Customer	Sell Product and Take Orders	Approx 25 orders per day, rising to 50 at peak times in Spring, summer, autumn and winter.	Sales Order. Can be by phone, received in the post or handed over by one of the travelling sales team. The flow contains all details needed to raise a sales order form. This includes the customer's account number and details of the items ordered. Sometimes a customer asks about stock levels during a sales call and this is answered by checking the stock levels database or the Low Stock list.
IO7	Customer Master File	Plan and Execute Marketing Campaign	Approx 3 times per month.	Customers for mailshot. Marketing use various criteria to include customers, trawling through the customer master file each time to select them.
IO8	Plan and Execute Marketing Campaign	Customers	Catalogues are sent 4 times per year with additional pages for new items being sent about once a month. Offers go out around 3 times a month.	Offers / Catalogue Mailshot. Customer name and address, brochures / catalogues / catalogue update pages.
IO9	Fill and Dispatch Orders	Courier	Approximately 25 per day, rising to 50 per day in peak times in Spring, summer, autumn and winter.	Delivery Notes. Each parcel has the delivery note attached. It contains a line for each item ordered, ticked when picked or crossed if put on back order.
IO10	Customer	Receive Goods Into Stock	Approx 500 per month	Returns Note. Customer account number, name, address, returns note number and, line by line, the product code and quantity returned. The stock room will have noted any damaged goods which are not fit to return to stock.
IO11	Supplier	Receive Goods Into Stock	Usually 4 per day, one from each major supplier. Each delivery note includes approximately 20 lines.	Delivery Note. Each delivery into stock received from suppliers is accompanied by a delivery note. It contains one line for each product ordered that details number ordered and number on back order.
IO12	Control Stock	Accounts	3 or 4 per day	Copy Purchase Order. When the stock room raises a purchase order a copy is passed to accounts so they can match against supplier invoices when they arrive (out of scope).
IO13	Control Stock	Customer Master File	Approximately 25 per day, rising to 50 per day in peak times in Spring, summer, autumn and winter. Also filled back-orders, approx 5-10 per week.	Dispatch Note. Each dispatch note is filed after a customer's order is filled. This doesn't include dispatch notes for orders that couldn't be filled completely (these are passed back to sales). A dispatch note also accompanies filled back orders.
IO14	Control Stock	Supplier	3 or 4 per day	Purchase Order. As stock levels approach their minimum holding levels they are added as a new line to an open purchase order for the preferred supplier. The Purchase order comprises supplier name and address, purchase order number, order code, quantity, item price and total line price.

As the Customer Master File datastore is used by areas that are out of scope, it is shown outside the top-level dfd process box boundary. This in turn means that any dataflows to it or from it need to have io-descriptions