Populating Software Repositories Incentives and Domain-Specific Software

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Populating Software RepositoriesIncentives and
Domain-Specific Software

• Jeffrey S. Poulin
• Journal of Systems and Software, 199530, p.
  187-199

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RSL

• RSL - Reusable Software Library
• Often the core of an organizational reuse
  strategy
• Do not guarantee success
• Depending on factors like availability of quality
  and useful software
• Domain-specific considerations most often
  determine the usefulness of software and should
  therefore influence the population of an RSL

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IBMs RTSC

• IBM formed the Reuse Technology Support Centre
  (RTSC) to promote formal reuse throughout the
  corporation
• Replacing informal reuse with a formal,
  systematic, process of exchanging quality
  components
• RTSC worked with designated representative from
  development sites
• RTSC sponsored enhancement to an existing library
  system so that it could support and control
  worldwide distribution of assets

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Populating the RSL

• High priority
• Incentive programs started to encourage
  depositing parts and using parts
• Slow progress
• Software available for general use stabilized
  around a set of low-level utilities and functions
• RTSC launched an incentive program to address
  this

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Reuse library considerations

• 1980s reuse programs focused on RSL
• Quite often the reuse program become the
  library
• Resources are spend on library related activities
• Little to show other than reports that cite a
  large library
• Library based reuse has resulted in a modes level
  of reuse, but it has not yielded a major change
  in reuse

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Lack of major change in RSL-based reuse

• Caused by the way organizations implement the RSL
• The theory of a creating a central, large
  repository seems good, but large RSLs suffer
  from a number of drawbacks

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The Reuse Library Progression

• Phase 1
• very few parts
• Phase 2
• many parts of low or poor quality
• Phase 3
• many parts of little or no use

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RSL overhead

• Overhead caused by the formality and rigor needed
  to manage large quantities of data
• Extensive classification scheme used to describer
  software components
• difficult to classify
• users need training
• Lack of standard method to classify software
• may help solving the training problem

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A corporate reuse library

• The IBM strategic RSL provides a
• central repository for sharing, managing, and
  reusing software-related products to company
  cites worldwide
• A distributed system of shared libraries
• The library is owned by the local organization
  and access is grants access to RSL users from
  other sites
• Based on a detailed classification scheme to
  support locating of relevant software
• Software in the library to be reused is copied to
  the local machine

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The quality standard of the RSL

• The RSL supports incremental stages of quality
• use-at-your-own-risk , .......,
  highly-trusted
• Provides supporting information to potential
  reusers
• design documents, integration instructions, test
  cases and legal information
• A component receives one of three quality
  ratings based in part on the completeness and
  quality of the supporting information

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Component management of the RSL

• To assist library managers
• Library access control
• Component user registration
• Version control
• Problem reporting
• Library shadowing
• Standard enforcement

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Incentive programs

• RTSC in 1991 faced a corporate RSL in the first
  stage of the three phases
• Feedback indicated a need for a wider selection
  of quality and useful software
• RTSC did not sponsor a centralized incentive
  program but encouraged and offered guidance to
  sites that wanted to start or have their own

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The supplier-consumer relationship

• The supplier
• those who write and and contribute quality
  reusable software and related information for
  others
• The reusers
• those who extract from the RSL and incorporates
  the software in their products rather than
  develop it again (the consumer)

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Reuse recognization

• Recognition programs usually allot points based
  on
• supplying software for reuse
• reusing software for reuse
• on the level of a developers participation in the
  program
• Accruing a certain number of point results in the
  individual receiving prizes or financial awards

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Recognizing suppliers

• When determining the proper recognition the
  program should address
• Participation
• allocating points to first.time users helps
  motivating developers and generates
• Popularity
• Provide more points to authors of very popular
  components encourages contributors to look for
  high reuse opportunities in their projects
• Value
• A large, robust and generalized component
  provides more economic benefit to the organization

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SIRBO

• Source Instructions Reused By Others
• Recognizes part suppliers
• The size (line of codes) for each component the
  individual contributes by the number of products
  or organizations actually using it.
• Helps ensure that suppliers do not receive
  recognition for unused software
• Rewards suppliers who identify widely needed
  functions
• Rewards contribution of large parts

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Recognizing users

• Reuse results from a business analysis showing
  possible financial savings to the organization
• Forms the basis for individual recognition
• Recognizing reusers also helps create a demand
  for reusable components
• RSI Reused Source Instructions
• The number of code lines in each reused component
• Credit is received first time component appears
  in a product

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Recognizing teams

• A team incentive can reward a number of group
  activities
• reward developer teams who achieve
• a pre-specified goal for the level of reuse
• receive an unforeseen exceptionally high level of
  reuse
• reward parts centre
• based on SIRBO
• Reward any team with a high number of individuals
  participating in reuse activities

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A corporate incentive program

• Local reuse programs at IBM started to develop
  and mature, but the overall quantity of parts
  available for general corporate use seemed to
  stabilize
• RTSC sponsored the development of reusable
  software The Parts Stimulation Program
• Moving from phase 1 without the pitfalls of phase
  2 and 3

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The Parts Stimulation Program strategy

• getting development organizations to realize that
  the projects would be more valuable if they made
  portions of the software reusable
• the program funded the dev. organizations to
  study their projects and the business issues
  related to reuse
• the Parts Stimulation Program funded the
  front-end expenses of conducting the reuse study
• performing a domain analysis
• developing the specification for the reusable
  parts
• completing a reuse business case detailing who
  else would benefit and the expected return of
  investments

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Incentive Program Results

• problems identifying candidate projects
• RTSC decided to fund alternative projects that
  might benefit the corporation
• reuse standard documents
• development tools
• study of an area of future development

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What makes software usable

• Programmers cannot reuse a software unless it is
  useful
• Categories for software
• Domain independent
• widest range of usefulness
• abstract data types, container classes, graphical
  ui,
• Domain specific software
• contributes to reuse within the problem domain
• device drivers, special purpose libraries
• Application specific software
• customized code needed to deliver a product
• tends to deal exclusively with application-unique
  functionality
• limited reuse

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Domain independent software

• Tends to consist of form 50-200 lines of source
  code
• single function or set of variables
• higher-level abstractions may include numerous
  interrelated data and functions that act together
  to perform a specific task
• high quality
• rarely contributes more than 15 20 to the
  total product
• making it easy to reuse domain independent
  reusable components is and easy, straight-forward
  and low cost way to get started in reuse

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Domain specific software

• Findings in various projects show high level of
  domain specific reuse
• The best results will come from a domain that
• has limited scope
• programmers understand
• has matured to a level of relative stability
• requires a lot of custom development based on a
  set of core functions
• Creating a domain library can be bottom-up or
  top-down