## 5 Key Findings and Critical Discussion
### Roadmap for the Implementation of Lean and Green  
Roadmaps guide what the present and future should look like [39]. They outline the company's current state (what it is) and its future state (what it should be) after implementing lean-green initiatives. The roadmap for this study was obtained based on evidence-based studies such as the work of the authors of [39; 107]. This roadmap (shown in Figure 5) aims to guide the effective implementation of lean and green models in improving environmental, social, and economic performance. It is divided into four phases.  
Phase 1: Assessment and Planning: This phase is designed to assess the current state of the organization's operations and plan for the transition to a sustainable future state. Assessments aid in identifying areas for operational and environmental enhancement and understanding potential challenges in implementing lean and green practices [71]. This phase provides strategic direction for implementing lean-green practices effectively. A company must demonstrate its lean-green strategic direction and improvement needs, contextualizing its fit into the operating environment, stakeholders, and benefits of lean adoption [108]. Assessment in this phase involves collecting field data through interviews of stakeholders and staff to understand their perception of sustainability and compliance with regulations and utilizing tools like sustainability value stream mapping (Sus-VSM) to assess sustainability metrics. After completing the assessment stage, a detailed plan for lean-green integration is developed; this involves outlining goals, strategies, KPI development, resource allocation, training, and capacity building.  
Phase 2: Capacity building and Employee training: This phase forms the competent, motivated team necessary for implementing and sustaining lean-green. Focusing on training, cultural alignment, and technological readiness, capacity building provides solutions to tackle implementation barriers like skills gaps, resistance to change, and technological deficiencies. Successful lean-green implementation in an organization requires trained staff. As evidenced by various examples from the SSA petroleum sector, capacity building is an enabler and a critical success factor in integrating lean-green [109]. This phase ensures that organizations are well-prepared to achieve their goals regarding sustainability and efficiency.  
Figure 5: Roadmap for the implementation of lean and green.  
Phase 3: Technology: This transformative phase will provide the SSA petroleum industry with the tools to achieve lean-green objectives. Advanced technologies can overcome regulatory hurdles and bridge technological gaps while improving sustainability performance. Technology applied in SSA has already brought about both environmental and economic benefits, such as gas-to-liquid technology (GTL) in Nigeria [110] and renewable energy in Ghana [111]. This could give opportunities for strengthening competitive advantage, green innovation, and entrepreneurship, as stated by the authors of [112].  
Phase 4: Monitoring and reporting: This phase is critical to the long-term success of sustaining continuous improvement in the petroleum industry's lean-green integration. It involves assessing strategy performance, monitoring sustainability metrics, ensuring regulatory compliance, and promoting stakeholder accountability and transparency [109]. Some of the key steps that should be followed include the following:  
* KPIs that align with the goals of lean-green, such as waste reduction, energy efficiency, and employee satisfaction, should be developed.
* Using technologies for the continuous monitoring of gas emissions and waste generation. For example, Chevron uses technologies to find and fix methane emissions.
* Produce reports using established reporting standards like the Global Reporting Initiative.