This version of SWEHB is associated with NPR 7150.2B. Click for the latest version of the SWEHB based on NPR7150.2C
5.2.2 The project manager shall identify, analyze, plan, track, control, communicate, and record software risks and mitigation plans in accordance with NPR 8000.4.
NPR 7150.2, NASA Software Engineering Requirements, does not include any notes for this requirement.
1.2 Applicability Across Classes
Class A B C CSC D DSC E F G H Applicable?
Key: - Applicable | - Not Applicable
A & B = Always Safety Critical; C & D = Not Safety Critical; CSC & DSC = Safety Critical; E - H = Never Safety Critical.
The purpose of risk management is to identify potential problems before they occur so that risk handling activities can be planned and invoked as needed across the life of the product or project. Risk handling activities are intended to mitigate adverse impacts on achieving the project's objectives. "Generically, risk management is a set of activities aimed at achieving success by proactively risk-informing the selection of decision alternatives and then managing the implementation risks associated with the selected alternative." 009 Identification and management of risks provide a basis for systematically examining changing situations over time to uncover and correct circumstances that impact the ability of the project to meet its objectives. NASA Procedural Requirement (NPR) 7150.2 states: "Identifying major risks, both technical and managerial, and determining how to lessen the risk helps keep the software development process under control." 276
During the past ten years, the importance and complexity of software at has grown enormously. With this change has come an increasing awareness of the substantial risks inherent in software development and the ineffectiveness of the usual method of dealing with risk. It is necessary to manage a list of software related risks throughout the software development lifecycle by the software development organizations even if the project office does not recognize or accept the software risks at the project level. The requirements is for the software organization to recognize that all software development has some level of risk. Each discipline of a project development team is to maintain a list of potential risks items for the development activities. The software risk process is handled in accordance with NPR 8000.4 process to the extent possible. The most important thing is that software organizations maintain and address risks throughout the software development process.
Software risks also factor into the software cost estimation process (see SWE-015).
This diagram from NASA/SP-2007-6105, NASA Systems Engineering Handbook, 273 provides an overview of a risk management process:
Guidance for each of the risk management steps is provided below. In addition to the guidance found in this Handbook, NASA users should consult Center Process Asset Libraries (PALs) for Center-specific guidance and resources related to continuous risk management.
Identify software risks
When identifying software risks, consider the following insights and suggestions:
- "Identify risks before they become problems. Communication is the center of the Risk Management paradigm (see NPR 8000.4, Agency Risk Management Procedures and Guidelines). Brainstorming is often used to identify project risks. People from varying backgrounds and points-of-view see different risks. A diverse team, skilled in communication, will usually find better solutions to the problems." 276
- Use a checklist to avoid "missing" risks that have been identified on previous projects. Topic 7.19 – Risk Management Checklists includes a number of software risks checklists.
- Add new risks to existing risk checklists for future projects.
- Review lessons learned from past projects.
- Include software assurance and/or software safety personnel on change control boards (CCBs) as roles specifically assigned to identify risks.
- Use a proactive and a continual process to identify risks.
- Assess the project to identify risks whenever there is a significant change in project circumstances.
- Include cost, performance, and schedule risks as well as technical or skill risks.
Capture identified risks
Once the team identifies the initial risk set, they are recorded with specific information useful to manage the risks.
When recording software risks, use the following recommendations:
- Risk identifier - A unique identification number assigned to each risk item; used to track a risk item from identification until project end
- Priority - A priority assigned to each risk item; used to establish when risks need to have actions taken, and how long risks may need to be watched or tracked before they are no longer a concern or can be closed; generally derived from results of analysis activities
- Probability - Likelihood the situation or circumstance will occur; generally part of the analysis activities
- Impact - Magnitude of the impact given that the event occurs; generally part of the analysis activities
- Exposure grade – Numerical value expressed as the product of the impact and probability; used for tracking and reporting purposes
- Time frame- Time frame of occurrence; gives the risk item a time context; determined by when the risk item will occur, relative to the risk reporting period; used in conjunction with the Exposure grade to determine Priority
- Immediate - within 30 days
- Near-Term - > 30 days ? 90 days
- Far-Term - > 90 days
- Risk statement- Statement of risk; objective is to arrive at a concise description of risk, which can be understood and acted upon; components and description of a statement of risk are:
- Condition: a single phrase or sentence that briefly describes the key circumstances, situations, etc., causing concern, doubt, anxiety, or uncertainty
- Consequence: a single phrase or sentence that describes the key, possible negative outcome(s) of the current condition.
Note: The minimum statement of risk is the condition. It is desirable to capture the originator’s assessment of the possible consequences of the risk to assure that it is given suitable weight during analysis; however, the explicit statement of consequence is not required, is often omitted, and can be subsequently added at the planning step.
- Assigned To - Individual or group responsible for tracking and reporting on the risk until closure
- Mitigation– The mitigation eliminates or reduces the risk by:
- Reducing the impact (by some degree or to zero)
- Reducing the probability (to a lower probability or zero)
- Shifting the timeframe (i.e., when action must be taken)
Note: recognize that mitigation may also introduce new risks to the software project
- Source - Assists in tracking identification
- Date opened - A beginning date that is a permanent date indicating when a risk is first identified
- Planned date closed - A planned closure date indicating when the risk is expected to be closed, based upon the software project lead’s experience; used to plan resources and track progress
- Date updated - Each risk shall be reported on during regular status meetings; this date reflects the last time an action was taken against a risk
- Date closed - A closure date indicating when the software project lead deemed a risk satisfactorily closed
- Closure rationale - Reason for closure; documents the rationale upon which the decision to close the risk was based.
Analyze software risks
Once the team identifies and records the initial set of risks, analysis needs to be performed to determine the likelihood (probability) and severity of the consequences of each risk.
When performing this analysis, many risk management guidebooks suggest including the following:
- Scenarios in which the risk could occur.
- Likelihood of occurrence.
One analysis method is a probabilistic risk assessment (PRA). Per NASA/SP-2007-6105, NASA Systems Engineering Handbook 273, "PRA is a scenario-based risk assessment technique that quantifies the likelihoods of various possible undesired scenarios and their consequences, as well as the uncertainties in the likelihoods and consequences.... For additional information on probabilistic risk assessments, refer to [NPR 8705.5A, Technical Probabilistic Risk Assessment (PRA) Procedures Guide for Safety and Mission Success for NASA Programs and Projects]." (Editor's Note: NPR 8705.3 has been updated to NPR 8705.5A in this quotation.) 346
Another recommendation is to model the scenarios and use those models to assess the consequences and determine the likelihood of a risk occurring.
One possible set of likelihood (or probability) classifications:
- Inevitable occurrence (5).
- Cannot prevent this event, no alternate approaches or processes are available.
- Very high probability of occurrence (4).
- Cannot prevent this event, but a different approach or process might prevent event.
- High probability of occurrence (3).
- May prevent this event, but additional actions will be required.
- Medium probability of occurrence (2).
- Current process is usually sufficient to prevent this type of event.
- Low probability of occurrence (1).
- Current process is sufficient to prevent this type of event.
One possible set of impact (or consequences) classifications:
(Note: The term technical includes everything that is not cost and schedule, e.g., safety, operations, programmatic.)
- Unacceptable (5).
- Technical - Unacceptable, no alternatives exist.
- Schedule - Can’t achieve key team or major project milestone.
- Cost - Team budget increase >15%.
- Major (4).
- Technical - Major reduction, but workarounds are available.
- Schedule - Key team milestone slip >1 month, or project critical path impacted.
- Cost - Team budget increase > 10%.
- Medium (3).
- Technical - Moderate reduction, but workarounds available.
- Schedule - Key team milestone slip <= 1 month.
- Cost - Team budget increase >5% or other teams impacted.
- Minor (2).
- Technical - Moderate reduction, same approach retained.
- Schedule - Additional activities required, able to meet need dates.
- Cost - Team budget increase < 5%.
- Minimal (1).
- Technical - Minimum reduction, same approach retained.
- Schedule - Additional activities required, able to meet need dates.
- Cost - Team budget increase < 2%,
The results of this step are used to rank the identified risks and the possible alternatives for those risks so that informed plans can be put into place to address those risks. NASA/SP-2007-6105, NASA Systems Engineering Handbook, 273 describes tools and techniques for analyzing and managing risks, including:
- Risk matrices - to facilitate discussions regarding "the status and effects of risk-handling efforts, and communicate risk status information."
- Failure mode effects analysis (FMEA) and failure modes, effects, and criticality analysis (FMECA) – "an ongoing procedure by which each potential failure in a system is analyzed to determine the results or effects thereof on the system, and to classify each potential failure mode according to its consequence severity."
- Fault tree analysis (FTA) - "identify potential failure modes for a product or process, to assess the risk associated with those failure modes, to rank the issues in terms of importance, and to identify and carry out corrective actions to address the most serious concerns."
Plan to address software risks
After the team identifies and analyzes the initial set of risks, a plan for managing those risks (and any risks identified later in the project life cycle) is needed. This plan may be standalone or be captured in the Software Development Plan/Software Management Plan (SDP/SMP) and updated throughout the project life cycle to reflect current risk management status. It is also important to inform providers, typically via their contract, that their risk management plans will be reviewed periodically by the acquirer.
Typical options for addressing risks include:
- Accepting all or part of a risk.
- Eliminating the risk.
- Mitigating the risk (reducing the likelihood, reducing the negative effects).
- Monitoring the risk.
- Conducting further research on the risk.
The risk management plan needs to include topics such as:
- Risk control and tracking steps describing what will be tracked.
- Risk control actions.
- Criteria for taking corrective actions.
- The project's continuous risk management activities which will identify potential technical problems before they occur and mitigate the impact of those problems on the outcome of the project.
- Risk owner, role responsible for responding to the risk.
The team needs to consider costs associated with managing, controlling, and mitigating risks when developing the risk management plan. This can be especially important for projects with limited or constrained budgets.
Project-level risk management plans need to describe coordination with program-level plans to ensure proper risk tracking and information sharing. Once the plan is created, it is reviewed and approved by an appropriate level of project management before it is implemented.
Track software risks
Risks that are not eliminated need to be tracked throughout the project life cycle to ensure their mitigation strategies remain effective. For low-risk items that are not formally included in the risk management plan, consider using a watch list so that they are not forgotten and to help ensure that they do not escalate to a higher level risk later in the project.
Additionally, conditions that the team has identified as risk triggers are also monitored and tracked until those situations are no longer risk factors. Risk status also needs to be tracked and weighed against risk criteria to determine if corrective action needs to be taken.
If a risk management tool is in use for the project, risks need to be added to and tracked using this tool. A tracking tool could be a simple spreadsheet or database for a small project, a tool purchased specifically for tracking risks, or part of an integrated tool used to track multiple aspects of the project.
Control software risks
When a risk occurs, action needs to be taken. Those actions should have been included in the risk management plan and need to be implemented in this step. Their effectiveness also needs to be measured so adjustments to the plan can be made, if necessary.
Communicate software risk information
Risk information is communicated to all relevant stakeholders throughout the project life cycle. Stakeholders include project managers, project technical personnel, test team members, and anyone else affected by or with the need to know about risks, their impact, and their mitigations. Project life cycle reviews are one mechanism for risk communication
Document software risks and mitigation plans
Recording software risks and mitigation plans is an activity that the team needs to do as part of all previous steps. Documentation could include:
- Analysis records decisions based on that analysis.
- Records of risk acceptance (approval signatures and reasons for acceptance).
- Records of planned mitigations and control mechanisms.
- A list of identified risks.
- A list of planned controls.
- Risk acceptance rationale.
NASA-STD-8719.13, NASA Software Safety Standard, 271 requires that "The software safety manager shall assure that risks affecting software safety are captured, addressed, and managed as part of program, project, and facility risk management processes, and those risks which could impose a system hazard are captured in the system hazard analyses."
The table below shows roles and responsibilities typical for continuous risk management:
Center safety and mission assurance (SMA) organizations
Provide risk management consultation, facilitation, and training to program/project organizations. 009
Review and approve risk management plan; ensure continuous risk management is implemented; designate the risk manager; ensure that key decisions are risk-informed; coordinate management of risks across affected projects or project elements.
Software Risk Manager
Overall responsibility for software risk management; ensures risk management plan developed. 009
Project software team members
Bring risks to management's attention; support Risk Manager in monitoring and controlling risks.
A recommended practice is that the Software Lead Engineer maintain a list of software risks independent of the program’s risk list. Frequently, the program risks are larger than any given software risk item. The software risk data should be maintained in an organizational database.
Additional guidance related to risk management may be found in the following related Topic in this Handbook:
4. Small Projects
Projects with limited budgets may consider using spreadsheets or small databases to track their project risks rather than purchase a tool for this purpose. Small projects could also consider using tools available at the Center level since those may have no associated purchase or lease costs.
- Technical Probabilistic Risk Assessment (PRA) Procedures for Safety and Mission Success for NASA Programs and Projects (Rev. w./Change 1)NPR 8705.5A, NASA Office of Safety and Mission Assurance, 2010. Effective Date: June 07, 2010, Expiration Date: June 07, 2022
Tools relative to this SWE may be found in the table below. You may wish to reference the Tools Table in this handbook for an evolving list of these and other tools in use at NASA. Note that this table should not be considered all-inclusive, nor is it an endorsement of any particular tool. Check with your Center to see what tools are available to facilitate compliance with this requirement.
No tools have been currently identified for this SWE. If you wish to suggest a tool, please leave a comment below.
6. Lessons Learned
The NASA Lessons Learned database contains the following lessons learned related to risk management:
- Lewis Spacecraft Mission Failure Investigation Board. Lesson Number 0625: Adopt Formal Risk Management Practices. "Faster, Better, Cheaper methods are inherently more risk prone and must have their risks actively managed. Disciplined technical risk management must be integrated into the program during planning and must include formal methods for identifying, monitoring and mitigating risks throughout the program. Individually small, but unmitigated risks on Lewis produced an unpredicted major effect in the aggregate." 512
- Identification, Control, and Management of Critical Items Lists. Lesson Number 0803: The Use of Probabilistic Risks Assessments: "Probabilistic risk assessments have proven to be useful procedures in providing product development teams with an insight into factors of safety and to strengthen critical item or single failure point retention rationale. Margins of safety have a strong influence on the acceptability of retaining potential failure modes or critical items if it can be proven that risk of failure is reduced to an acceptably low level." 524
- Flight Anomaly of Atmospheric Trace Molecule Spectroscopy (ATMOS) Instrument, Risk Assessment. Lesson Number 0272: Lesson Learned No. 2 states: "Low-cost Shuttle Transportation System (STS)-borne experiments with plans for repeated flights, exemplified by the Atmospheric Trace Molecule Spectroscopy (ATMOS) spectrometer, require risk assessments different from those used for single launch experiments." 500