This article provides information about selecting product component solutions considering the major areas, limitations, issues etc. The article defines the Technichal Solutions for the product-component solutions based on CMMI standards.
SG 1 Select Product-Component Solutions
Product or product-component solutions are selected from alternative solutions.
Alternative solutions and their relative merits are considered in advance of selecting a solution. Key requirements, design issues, and constraints are established for use in alternative solution analysis.
Architectural features that provide a foundation for product improvement and evolution are considered. Use of commercial off-the-shelf (COTS) product components are considered relative to cost, schedule,
performance, and risk. COTS alternatives may be used with or without modification. Sometimes such items may require modifications to aspects such as interfaces or a customization of some of the features to
better achieve product requirements.
One indicator of a good design process is that the design was chosen after comparing and evaluating it against alternative solutions. Decisions on architecture, custom development versus off the shelf, and product-component modularization are typical of the design choices that are addressed.
Sometimes the search for solutions examines alternative instances of the same requirements with no allocations needed to lower level product components. Such is the case at the bottom of the product architecture. There are also cases where one or more of the solutions are fixed (e.g., a specific solution is directed or available product components, such as COTS, are investigated for use).
In the general case, solutions are defined as a set. That is, when defining the next layer of product components, the solution for each of the product components in the set is established. The alternative
solutions are not only different ways of addressing the same requirements, but they also reflect a different allocation of requirements among the product components comprising the solution set. The objective is to optimize the set as a whole and not the individual pieces.There will be significant interaction with processes associated with the Requirements Development process area to support the provisional allocations to product components until a solution set is selected and final allocations established.
Product-related life-cycle processes are among the product-component solutions that are selected from alternative solutions. Examples of these product-related life-cycle processes are the manufacturing and the
support processes.
SP 1.1 Develop Detailed Alternative Solutions and Selection Criteria
Develop detailed alternative solutions and selection criteria.
For Integrated Product and Process Development
The activity of selecting alternative solutions and issues to be subject to decision analyses and trade studies is accomplished by the involvement of relevant stakeholders. These stakeholders represent both business and technical functions and the concurrent development of the product and the product-related life-cycle processes (e.g., manufacturing,support, training, verification, and disposal). In this way, important issues surface earlier in product development than with traditional serial development and can be addressed before they become costly mistakes.
Detailed alternative solutions are an essential concept of the Technical Solution process area. They provide more accurate and comprehensive information about the solution than nondetailed alternatives. For example, characterization of performance based on design content rather than on simple estimating enables effective assessment and understanding of environment and operating concept impacts. Alternative solutions need to be identified and analyzed to enable the selection of a balanced solution across the life of the product in terms of cost, schedule, and technical performance. These solutions are based on proposed product architectures that address critical product qualities. Specific practices associated with the Develop the Design specific goal provide more information on developing potential product architectures that can be incorporated into alternative solutions for the product.
Alternative solutions span the acceptable range of cost, schedule, and performance. The product-component requirements are received and used along with design issues, constraints, and criteria to develop the
alternative solutions. Selection criteria would typically address costs (e.g., time, people, money), benefits (e.g., performance, capability,effectiveness), and risks (e.g., technical, cost, schedule).Considerations for detailed alternative solutions and selection criteria include the following:
· Cost (development, procurement, support, product life cycle)
· Technical performance
· Complexity of the product component and product-related life-cycle processes
· Robustness to product operating and use conditions, operating modes, environments, and variations in product-related life-cycle processes
· Product expansion and growth
· Technology limitations
· Sensitivity to construction methods and materials
· Risk
· Evolution of requirements and technology
· Disposal
· Capabilities and limitations of end users and operators
The considerations listed above are a basic set; organizations should develop screening criteria to narrow down the list of alternatives that are consistent with their business objectives. Product life-cycle cost, while
being a desirable parameter to minimize, may be outside the control of development organizations. A customer may not be willing to pay for features that cost more in the short term but ultimately decrease cost
over the life of the product. In such cases, customers should at least be advised of any potential for reducing life-cycle costs. The criteria used in selections of final solutions should provide a balanced approach to
costs, benefits, and risks.
Typical Work Products
1. Alternative solution screening criteria
2. Evaluations of new technologies
3. Alternative solutions
4. Selection criteria for final selection
Subpractices
1. Identify screening criteria to select a set of alternative solutions for consideration.
2. Identify technologies currently in use and new product technologies for competitive advantage.
The project should identify technologies applied to current products and processes and monitor the progress of currently used technologies throughout the life of the project. The project should identify, select, evaluate, and invest in new technologies to achieve competitive advantage. Alternative solutions could include
newly developed technologies, but could also include applying mature technologies in different applications or to maintain current methods.
3. Generate alternative solutions.
4. Obtain a complete requirements allocation for each alternative.
5. Develop the criteria for selecting the best alternative solution.
Criteria should be included that address design issues for the life of the product, such as provisions for more easily inserting new technologies or the ability to better exploit commercial products. Examples include criteria related to open design or open architecture concepts for the alternatives being evaluated.
6. Develop timeline scenarios for product operation and user interaction for each alternative solution.
The following specific practice appears in the continuous representation as SP 1.1-1, but is subsumed in the staged representation by SP 1.1, Develop Detailed Alternative Solutions and Selection Criteria. The specific practice is presented here only as informative material.
SP 1.1-1 Develop Alternative Solutions and Selection Criteria
Develop alternative solutions and selection criteria.
Alternatives are based on potential product architectures and span a design space of feasible solutions. The Design Product or Product Component specific practice of the Develop the Design specific goal
contains more information about developing potential product architectures to incorporate into alternative solutions for the product.
As selections are made, the design space may be constricted and other alternatives examined until the most promising (i.e., optimal) solutions that meet requirements and criteria are identified. The selection criteria
identify the key factors that provide a basis for the selection of the solution. These criteria should provide clear discrimination and an indication of success in arriving at a balanced solution across the life of
the product. They typically include measures of cost, schedule, performance, and risk.
The alternative solutions evaluated frequently encompass alternative requirement allocations to different product components. These alternatives may also be structured to evaluate the use of COTS solutions in the product architecture. Processes associated with the Requirements Development process area would then be employed to provide a more complete and robust provisional allocation of requirements to the alternative solutions.
Selection of the best solution establishes the requirements provisionally allocated to that solution as the set of allocated requirements. The circumstances in which it would not be useful to examine alternative
solutions are infrequent in new developments. However, developments of precedented product components are candidates for not examining, or only minimally examining, alternative solutions.
Typical Work Products
1. Alternative solutions
2. Selection criteria
Subpractices
1. Establish and maintain a process or processes for identifying solution alternatives, selection criteria, and design issues.
Selection criteria are influenced by a wide variety of factors driven by the requirements imposed on the project as well as the product life cycle. For example, criteria related to mitigating cost and schedule risks may influence a greater preference for COTS solutions provided such selections do not result in unacceptable risks for the remaining product components to be developed. When using existing items, such as COTS, either with or without modification, criteria dealing with diminishing sources of supply or technological obsolescence should be examined, as well as criteria capturing the benefits of standardization,
maintaining relationships with suppliers, and so forth. The criteria used in selections should provide a balanced approach to costs, benefits, and risks.
2. Identify alternative groupings of requirements that characterize sets of solution alternatives that span the feasible design space.
Effective employment of COTS alternatives can provide special challenges. Knowledgeable designers familiar with candidate COTS alternatives may explore architectural opportunities to exploit potential COTS payoffs.
3. Identify design issues for each solution alternative in each set of alternatives.
4. Characterize design issues and take appropriate action.
Appropriate action could be to characterize the issues as a risk for risk management, adjust the solution alternative to preclude the issues, or reject the solution alternative and replace it with a different alternative.
5. Obtain a complete requirements allocation for each alternative.
6. Document the rationale for each alternative set of solutions.
SP 1.2 Evolve Operational Concepts and Scenarios
Evolve the operational concept, scenarios, and environments to describe the conditions, operating modes, and operating states specific to each product component.
Operational concepts and scenarios are evolved to facilitate the selection of product-component solutions that, when implemented, will satisfy the intended use of the product. Operational concepts and
scenarios document the interaction of the product components with the environment, users, and other product components, regardless of engineering discipline. They should be documented for operations,
product deployment, delivery, support (including maintenance and sustainment), training, and disposal and for all modes and states.
The environments (operating, support, training, etc.) also need to be evolved. The environment of any given product component will be influenced by other product components as well as the external
environment.
Typical Work Products
1. Product-component operational concepts, scenarios, and environments for all product-related life-cycle processes (e.g., operations, support, training, manufacturing, deployment, fielding,delivery, and disposal)
2. Timeline analyses of product-component interactions
3. Use cases
Subpractices
1. Evolve the operational concepts and scenarios to a degree of detail appropriate for the product component.
2. Evolve the operational environments for the product components.
The environments may include thermal, stress, and electromagnetic and other elements that need to be documented.
SP 1.3 Select Product-Component Solutions
Select the product-component solutions that best satisfy the criteria established.
Selecting product components that best satisfy the criteria establishes the requirement allocations to product components. Lower level requirements are generated from the selected alternative and used to develop the product-component design. Interface requirements among product components are described, primarily functionally. Physical interface descriptions are included in the documentation for interfaces
to items and activities external to the product.
The description of the solutions and the rationale for selection are documented. The documentation evolves throughout development as solutions and detailed designs are developed and those designs are implemented. Maintaining a record of rationale is critical to downstream decision making. Such records keep downstream stakeholders from redoing work and provide insights to apply technology as it becomes available in applicable circumstances.
Typical Work Products
1. Product-component selection decisions and rationale
2. Documented relationships between requirements and product components
3. Documented solutions, evaluations, and rationale
Subpractices
1. Evaluate each alternative solution/set of solutions against the selection criteria established in the context of the operating concepts, operating modes, and operating states.
2. Based on the evaluation of alternatives, assess the adequacy of the selection criteria and update these criteria as necessary.
3. Identify and resolve issues with the alternative solutions and requirements.
4. Select the best set of alternative solutions that satisfy the established selection criteria.
5. Establish the requirements associated with the selected set of alternatives as the set of allocated requirements to those product components.
6. Identify the product-component solutions that will be reused or acquired.
7. Establish and maintain the documentation of the solutions,evaluations, and rationale.
