Essence-Based, Goal-Driven

Adaptive Software EngineeringProfessor June Sung Park

Korea Advanced Institute of Science and Technology (KAIST)

Workshop on a General Theory of Software Engineering

State of Software Engineering Project

How is the

project

going?

Oh, I guess

its goingOK?

Alphas in Essence Kernel

Yeah, this

is the

current

state.

st = [st , ], i.e., st = Really?

Youresure?

Essence Alpha project state spaceproject state vector

Alpha State Checklists

I use state

checklists.

How do

you know

where we

are?

Alpha State Card state checklistEssence Alpha Card

Goal State

So whatsnext to do?

Well, I will show

you how I

determine the

next activities

to achieve the

next goal state.

goal statecurrent state

ActivityActivity SpaceAlpha StateSoftware Engineering PracticeEssence KernelProject Process

Alpha State at Completion of Activity Spacetarget state of the activity space

prescribed in Essence kernel

Alphas affected by

the activity space

Semi-Markovian Decision Process of

Software Engineering

A project method can be viewed as a stochastic decision process on state space and activity space A with a nondeterministic state transition function .

Essence prescribes a healthy progress of the state of software projects (i.e., alpha

states) and checklists to assess the state. You may use them to evaluate the current

state and set the next goal state.

It also suggests completion criteria for activity spaces in terms of alpha states.

By mapping practice activities to Essence activity spaces, you may get a goal list (i.e.,

a list of checkpoints to satisfy) for each activity. This paper provides a new algorithm

to select the next activities to perform to achieve a goal state of the project.

Activity(A)Activity Space(V) Mapping()

You may easily

combine multiple

practices, if described

using Essence kernel,

into your project

method without

overlaps and gaps.

software engineering practice

Essence Alpha practice work product Essence Activity Space practice activity

Alpha State when an Activity is Donetarget state of the activity activity space containing the activity

Activity-State Mapping Algorithm

The Activity-State Mapping Algorithm produces a goal list () for each project activity .

Activity-State Mapping Algorithm

Step 1: Design the software engineering method for a project determining the set of

activities to be performed.

Step 2: Assign each activity to one or more activity spaces ( ).

Step 3: Repeat for each activity listed in Step 1.

Step 3.1: List the alpha states that are pursued by the activity spaces that contain the

activity ( ).

Step 3.2: Collect all the checkpoints corresponding to the alpha states listed in Step

3.1, and merge the checkpoints to obtain the default activity goal list ().

Step 4: Customize the default activity goal lists by modifying the set of alphas, alpha

states, alpha state checklists, and the alpha states to be pursued by each activity

space or each activity.

Goal-Activity Cover Algorithm

Given the projects goal state at epoch t, a set of activities can be chosen to pursue to achieve the goal state.

Set can be obtained by the minimal set of activities whose goal lists, () for all , cover the checklists for the projects goal state.

Goal-Activity Cover Problem

Input: The goal state +1, the set of() for all , and a family of subsets of

Goal: Choose a subfamily of with thesmallest cardinality given by

= arg min

( +1) .

Goal-Activity Cover Algorithm

1 : = ;2 Repeat

3 = arg

() ( +1) ;

4 = {};5 = {};6 +1 = ( +1) ();7 For each 8 () = () ();9 End;

10 Until +1 = +1 = ;

Automation Tool

OK, I see

the value

of Essence

now.

Well, I have shown you how I

determined the next activities to

perform to achieve the next goal

state.

This can be automated if we use a

tool that supports the description

of practices using the Essence

kernel, and build a database of

checklists for alpha states.

Conclusion

Essence kernel can be used to describe practices, merge them into a project method, monitor health and progress of the project, and adaptively determine project goals and activities based on the current state assessment.

This is made possible by developing a set of checklists for every meaningful state along every important dimension, and use the same set of checklists consistently in assessing the current state, setting up the completion state of each activity, planning the future goal state of the project, and determining the set of activities to perform to fulfill the goal state.

Essence provides generic checkpoints, or general symptoms of hidden specific states. A project team should extend and customize the Essence-provided checklists as an ongoing effort to make them specifically relevant to their project context.

Building a good set of checklists is a learning process and an important way to optimize the team performance.

Wed betterlearn and use

Essence.

I think so,

too. It really

makes our

team agile.