Project Planning

Overview

To frame our discussion, consider:

What is the role of planning in facilitating the development of software?

How do plans assist in the management of project resources?

How do we arrive at effort and cost estimates for software products?

OUTLINE

Planning
Managing
Project Estimation
References

The objective of software project planning is to provide a framework that enables the project manager to estimate the resources, cost, and schedule. Project planning is an iterative process with periodic stepwise refinements.

Planning is used to find credible ways to produce results with limited resources and limited schedule flexibility.
Planning is negotiating compromises in completion dates and resource allocation.
Planning is identifying and accommodating the unforseen.
Planning is blending the efforts of many people to produce a product that satisfies the customer's need.

The project manager is largely responsible for all project planning. The designers and developers of the project following the recommendations of each activity should produce artifacts and feedback which provides the project manager with a measure of project progress. The project manager reviews these measures and decides what if any corrective actions are necessary to keep the project on schedule. These actions may involve reallocating resources, adjusting schedule, relaxing requirements, increasing training, etc.

A new project is initiated by a statement of work (SOW), what we are calling the problem definition. The SOW describes the software product that the customer wants you to produce. The project manager should initiate a System Design activity to produce an architecture for the system. This may require that the project manager first select an appropriate method for performing a first pass at Requirements Elicitation and Requirements Analysis, and perform those activities before enough information is available to the designers to create an architecture.

Long-term plan

The long-term project plan describes the resources to be used for the entire length of the project. It should detail what is to be done and by whom.

Short-term plan

A tentative short-term plan helps the project team coordinate the activities of the project, so they can work at an effective rate. The schedule will reflect:

each team members abilities to perform the activities
the resources utilized in the project
the groups overall ability to perform

The tentative short-term project plan should follow a set of activities that needs to be performed in order to proceed with the successive activities for the next week.

Risk

The short-term plan certainly encompasses plenty of risks. The best way to handle risks are to:

identify the risk.
find a resolution for this risk within the time frame of the project.
figure out the chance this risk will occur.

Resources

Human	Select the individuals with the necessary skills to accomplish the activity.
Hardware	Specify the development system, the target system, and other hardware elements.
Software	Project management Tools Support Tools Analysis and Design Tools Programming Tools Testing Tools Prototyping Tools

Managing

Time	The time needed to build system is related to the size of the system, which in turn is related to the number of functions desired, and the number of individuals involved and their productivity. 40-20-40 60-15-25
Information	Project documentation Agreed upon changes
Organization	Identified roles of individuals and the expectations of those roles.
Quality	The characteristics of the product that in a real sense govern its value to the customer.
Money	Software is labor intensive. Controlling and managing money is typically a matter of controlling labor costs.

Project Estimation

The Problem:

Given the information in the system definition, determine the cost of the software product and the development effort.

Solution:

1. Use a simple decomposition technique to generate project cost and effort estimates. Divide the project into major functions and tasks, then produce the cost or effort estimate for each of these.

2. Develop an empirical model for software cost and effort. Construct a model based on historical data from prior projects. Establish the values of the given set of parameters for the current project, and the model produces the estimates requested.

Cost/Effort

Units of measure?

Cost - $

Effort - person-month

Relationship

C = f(E)

Cost = cost/person-month * estimated person-months

What is effort related to?

Coverage

Requirements through delivery?

Design through delivery?

Requirements through maintenance?

Algorithmic Models

where a, b, and c are constants and the function f is a correction dependent on the values of the vector x (sometimes referred to as cost drivers).

a, b, and c are derived through the use of regression analysis on data from previous projects.

Cocomo

where b and c are constants that are a function of the project type.

Project Types

Organic	b=2.4, c=1.05
	A relatively small team develops software in a known environment. Those involved generally have significant experience with projects of this type. These tend to be small projects.
Embedded	b=3.0, c=1.12
	These projects involve the development where the intended environment poses significant constraints. The product is "embedded" in an environment which is inflexible.
Semidetached	b=3.6, c=1.20
	This is an intermediate. The team may show a mixture of experience and inexperienced people. The project may be larger than that in the organic type.

Cost Drivers

Cost Drivers	Rating
Cost Drivers	very low	low	nominal	high	very high	extra high
Product Attributes
Reliability	.75	.88	1.00	1.15	1.40
Data base		.94	1.00	1.08	1.16
Product Complexity	.70	.85	1.00	1.15	1.30	1.65
Computer Attributes
Execution Time			1.00	1.11	1.30	1.66
Main Storage			1.00	1.06	1.21	1.56
Virtual Machine Volatility		.87	1.00	1.15	1.30
Computer Turnaround Time		.87	1.00	1.07	1.15
Personnel Attributes
Analyst Capabilities	1.46	1.19	1.00	.86	.71
Applications Experience	1.29	1.13	1.00	.91	.82
Programmer Capability	1.42	1.17	1.00	.86	.70
Virtual Machine Experience	1.21	1.10	1.00	.90
Prog. Lang. Experience	1.14	1.07	1.00	.95
Project Attributes
Use of modern prog. Tech.	1.24	1.10	1.00	.91	.82
Use of Software Tools	1.24	1.10	1.00	.91	.83
Development Schedule	1.23	1.08	1.00	1.04	1.10

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References

Boehm, B. (1981) Software Engineering Economics. Englewood Cliffs, NJ: Prentice-Hall.

van Vliet, H. (1993) Software Engineering: Principles and Practice. New York: John Wiley.