Software Project Planning

1
Software Project Planning

• CS 414 Software Engineering I
• Donald J. Bagert
• Rose-Hulman Institute of Technology
• December 12, 2002

2
Outline

• Definition and Objectives
• Scope
• Resources
• Estimation Methods
• To Build or Not to Build?
• The Project Plan
• Project Management
• Summary

3
Definition and Objectives

• Software project planning is the process of
• determining what the scope and available
  resources for a project,
• estimating the costs, total effort and duration
  of the project required to develop and deliver
  the software,
• determining the feasibility of the project,
• deciding on whether or not to go forward with
  project implementation,
• creating a plan for the successful on-time and
  within budget delivery of reliable software that
  meets the clients needs, and
• updating the plan as necessary throughout the
  project lifetime.
• Planning is primarily the job of the Project
  Manager

4
Scope

• The scope of the project describes the desired
  functionality of the software, and what
  constraints are involved
• Therefore, project scope is determined as part of
  the analysis process by the requirements team
• The project manager then uses the scope that has
  been defined in order to determine project
  feasibility, and to estimate what costs, total
  effort and project duration will be involved in
  engineering the software

5
Scope (continued)

• So does that mean that planning should come after
  requirements?
• No. Project planning is actually an iterative
  process, which starts at the beginning of the
  project, and continues throughout

6
Resources

• Human Resources
• Includes overhead
• By far the most dominant aspect of software costs
  and effort
• Software Resources
• COTS
• In-house developed software and tools
• Reusable artifacts (e.g. design patterns)
• Historical data (helps with cost/effort
  estimation)
• Note that there is usually not much involving
  physical resources (except as it relates to
  overhead)

7
Estimation Methods

• Estimation may be the most difficult task in an
  entire software project
• Almost all software cost estimation is related to
  human resources
• This is different from other engineering
  disciplines, which have to deal with more
  physical resources

8
Estimation Methods (continued)

• Estimation Techniques
• Using historical data
• Decomposition techniques
• Empirical models
• A combination of any or all of the above
• Many estimation techniques use some estimate of
  size, such as
• KLOC (Thousands of lines of code)
• FP (Function points)
• OP (Object points)

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Estimation Methods (continued)

• Historical Data
• Pretty self-explanatory
• Uses track record on previous projects to make
  estimates for the new project
• Main Advantage
• Is specific to that organization
• Main Disadvantages
• Continuous process improvement is sometimes hard
  to factor in
• Some projects may be very different than previous
  ones

10
Estimation Methods (continued)

• Examples of Decomposition Techniques
• Problem-based Use functional or object
  decomposition, estimate each object, and sum the
  result
• Estimates either use historical data or empirical
  techniques
• Process-based Estimate effort and cost for each
  task of the process, then sum the result
• Estimates use historical data
• Main advantage of decomposition techniques
• Easier to estimate smaller parts
• Main disadvantage
• More variables involved means more potential
  errors

11
Estimation Methods (continued)

• Empirical Models
• Uses formulae of the form
• g f(x)
• where g is the value to be estimated (cost,
  effort or project duration) and x is a parameter
  such as KLOC, FP or OP
• Most formulae involving KLOC consistently show
  that there is an almost linear relationship
  between KLOC and estimated total effort
• Main advantage of empirical models
• Easy to use
• Main disadvantage
• Models are usually derived from a limited number
  of projects, but are used in a more generalized
  fashion

12
Estimation Methods (continued)

• COCOMO
• The most well-known empirical model
• First introduced by Barry Boehm in 1981
• Has since evolved into a more comprehensive model
  named COCOMO II
• http//sunset.usc.edu/research/cocomosuite/index.h
  tml
• COCOMO II has a variety of formulae
• For various stages of the project
• For various size parameters (KLOC, FP, object
  points)
• For various types of project teams

13
To Build or Not to Build?

• During early stages of planning, critical
  decisions must be made due to estimation results
  e.g.
• Whether or not to bid on a contract, and if so,
  for how much
• Whether or not build software, or to purchase
  existing software that has much of the desired
  functionality
• Whether or not to subcontract (outsource) some of
  the software development

14
The Project Plan

• Actual description of
• The tasks to be done
• Who is responsible for the tasks
• What order tasks are to be accomplished
• When the tasks will be accomplished, and how long
  they will take
• The Project Plan is updated throughout the
  project

15
The Project Plan

• For this course
• CS 414 Project Plan Template
• The Project Plan should be consistent with the
  Weekly Reports
• What tasks should go into your teams Project
  Plan?

16
Project Management

• Project planning is only part of the overall
  management of the project
• Other project management activities include
• Risk analysis and management
• Assigning and organizing project personnel
• Project scheduling and tracking
• Configuration management

17
Project Management

• Project Management (across disciplines) is
  actually considered a whole separate field from
  software engineering
• The Project Management Institute
  (http//www.pmi.org) has actually developed a
  entire Body of Knowledge for project management
• However, there are some aspects of software
  project management that are unique to the
  management of software

18
Summary

• The primary objective of software project
  planning is to plan for the successful on-time
  and within budget delivery of reliable software
  that meets the clients needs
• Project scope should be determined through
  requirements analysis and used for planning by
  the project manager
• The primary resources needed for a software
  project are the actual developers

19
Summary (continued)

• Various techniques are available for the
  estimation of project cost, total effort and
  project duration
• Early on in a project decisions must be made on
  whether or not to proceed with a project, and
  whether or not to buy or build the software
• The project tasks, schedule and resource
  allocation is all part of the Project Plan
• Project planning is only part of the project
  management process