Elephant Carpacio

from Alistar Cockburn workshop (https://docs.google.com/document/d/1TCuuu-8Mm14oxsOnlk8DqfZAA1cvtYu9WGv67Yj_sSk/pub)

Overview

Releasing software is actually releasing decisions. Every delivered decision is actually a choice that can be wrong. So what we release in production can contains a set of wrong decisions. Furthermore a decision can depend on other decisions, so a failure on one early decision impact the subsequent ones. This mean that rework an early decision is more difficult if not impossible to do. Thereby a failure in one early decision can consequently challenge the entire delivery.

How to fix? reducing the amount of decision per release, and organize the release like a business test on the delivered decision. If some assumption was wrong you can still rework and adjust, before going on.

Postulates

Taking a lot of decisions without any feedback increase the risk of failure.

Reducing the amount of decisions in a delivery reduce the risk, and enable an early feedback

Learning outcomes

How to slice large applications into 1-day to 1-week requests, business perspective.
How to slice application requests into 15-30 minute work slices, programming perspective.

Assignment

Accept inputs from the user:

Quantity: a number of items,
Price: a price for the item,
State: a 2-letter state code

Compute the price of the order, giving a discount based on order value (not number of items), adding state tax based on the state and discounted order value.

Order value	Discount rate	State	Tax rate
$ 1,000	3%	UT	6.85%
$ 5,000	5 %	NV	8.00%
$ 7,000	7%	TX	6.25%
$ 10,000	10%	AL	4.00%
$ 50,000	15%	CA	10.00%

Slices

#	Inputs	Output	Value
1.	no input	Output: Hello world	setup the project
2.	Quantity and Price	Output: echo inputs	having a walking skeleton
3.	Quantity and Price	Output: order value with no discount and fixed UT tax	Possibility to enable a test in UT
4.	Quantity, Price and State	Output: order value with no discount and tax based on UT tax + echo State	verify that the enter State is correct
5.	Quantity, Price and State	Output: order value with no discount and Tax based on UT tax	Automatic calculation of UT tax from the mapping of State with tax_rate
6.	Quantity, Price and State	Output: order value with no discount and Tax based on UT and NV State	Go live on NV
7.	Quantity, Price and State	Output: order value with no discount and Tax based on UT, NV, TX	Go live on TX
8.	Quantity, Price and State	Output: order value with no discount and Tax based on UT, NV, TX, AL	Go live on AL
9.	Quantity, Price and State	Output: order value with no discount and tax based on UT, NV, TX, AL, CA	Go live on CA
10.	Quantity, Price and State	Output: order value with discount on $1,000 and tax based on UT, NV, TX, AL, CA	Possibility to put a discount over $1,000
11.	Quantity, Price and State	Output: order value with discount on $5,000 and tax on all State	Possibility to put discount over $5,000
12.	Quantity, Price and State	Output: order value with discount on $7,000 and tax on all State	Possibility to put discount over $7,000
13.	Quantity, Price and State	Output: order value with discount on $10,000 and tax on all State	Possibility to put discount over $10,000
14.	Quantity, Price and State	Output: order value with discount on $10,000 and tax on all State	Possibility to put discount over $50,000
15.	Quantity, Price and State from fancy cli	Output: order value with discount on $10,000 and tax on all State	User insert input through interface

lucalorenzon / elephantcarpacio Goto Github PK