WHAT IS SLACK, AND WHY IS IT NEEDED?
What should you do when you must return home as fast as possible during rush hour? Choosing an alternate route using your smartphone’s map app to avoid traffic after looking at different ways before leaving is possible. This example of flexibility is a good illustration of what Slack means, which is based on the ability of people to adjust and be flexible when faced with uncertainties.
Slack provides a way to handle uncertainties and fluctuations in a planned or unplanned manner by utilizing various types of resources. Slack is broader than the use of more unproductive resources. Resources already in use can be reused to manage uncertainties and fluctuations. Space can also open up opportunities for innovation by allowing organizations and individuals to experiment with new approaches (Bourgeois, 1981; Lawson, 2001).
Buffer is one of the most well-known types of Slack. It is defined as a cushion to ensure processes are protected from fluctuations. Pads can tackle the existing, known variations, assisting in achieving the desired outcome (Alves & Tommelein, 2003; Buchmann & Slorup, 2014). However, different types of Slack could address other kinds of uncertainty or demands from organizations.
From a business perspective, Slack is a resource needed to satisfy demand or implement actions at the strategic level (e.g., creating new products and forming coalitions). From the perspective of production systems, the need for Slack arises due to the complexity of construction projects. Construction projects must be seen as complicated sociotechnical structures (CSSs).
The complexity of building projects or any other CSSs is characterized by their structure’s complexity and their uncertain nature (Williams, 1999). Structural complexity is present in systems that have many interrelated components. The level of complexity is correlated with the quantity and quality of ingredients and the strength of their interdependencies. Uncertainty is connected to the objectives of the project (i.e., the degree to which well-defined the goals are) and the methods (i.e., the degree to which well-defined the means of attaining these targets are). It is also referred to as a predictable type of uncertainty. However, uncertainty could be described as indeterminacy, where knowledge is absent about an event.
In CSSs, a lot of the uncertainty is due to the influence of social and human factors or organizational circumstances, which make the operation of a system challenging to forecast and manage. Complexity can make it difficult for individuals to comprehend, describe and manage the systems. In addition, highly complex projects or plans result in outcomes that are not predictable, i.e., outcomes that are not predictable in the future.
Figure 1 is a conceptual map that shows connections between concepts studied during this work (see Formoso et al. 2021). This map can be divided into three areas: (i) Why is Slack needed? (antecedents); (ii) what exactly is the definition of Slack? (classification as well as development) (antecedents); (iii) what are the effects of Slack? (consequences).
Figure 1. Slack conceptual map (from Formoso and Co. 2021)
HOW TO IMPLEMENT SLACK
Some slack resources include equipment, inventories, time cash, people, and information. These resources can be utilized to supply CSSs with the following:
- Redundancy Additional resources (in more) which are available, e.g., redundant processes or functions.
- Flexibility is a term used to describe resources that can be utilized in various ways – e.g., multi-skilled employees, multi-purpose equipment, and changes made by the workforce to adapt to changes in events.
Secondary strategies for Slack include a margin of maneuver as a mix of flexibility and redundancy based on the autonomy of the individuals (or groups) of individuals or work in progress (WIP), which is a form of redundancy. The margin of maneuver is a way to determine the ways resources can be modified following the current and necessary circumstances as well as the current conditions; WIP (a type of Slack commonly seen when working on construction) can be seen as an inventory of products that are not finished or backlogs of workspaces which are frequently employed as a way to deal with the absence of reliability in flow.
WHAT ARE THE IMPACTS OF SLACK
In CSSs, anticipating the emergence of situations is complex, and Slack could be considered a crucial strategy to reduce risk. Risks in construction projects are usually managed in a dispersed method in management processes like design, procurement and quality, safety, production control, and planning. Production teams also perform informal risk management throughout their everyday tasks when they have to evaluate trade-offs and prioritize the distribution of resources, e.g., when assessing the risk of working over to complete an assignment.
The significant positive outcomes of Slack can be found below. They affect the efficiency of construction projects by increasing productivity, providing more excellent value for the clients, and reducing the length of the project.
- Resilience The capability of a system to adapt its operation before or after certain events, such as changes in the environment, disruptions, or opportunities, so that it can continue operations in unexpected or expected circumstances (Hollnagel & Co., 2015). Reliability: the ability of an entire system or its parts to perform the functions required under specified conditions for a predetermined duration (Rausand & Hoyland, 2004).
- Robustness is the capability of a system to remain functional when subjected to various environmental or internal disturbances and conditions. Robustness can be observed when a sufficient array of options can withstand disruptions (Saurin 2017, 2017).
- The flexibility of the output The ability to adapt products to meet specific customer demands without incurring significant costs for transitions or causing substantial variations in the performance outcomes (Petroni & Bevilacqua, 2002). It is in direct relation to the strategy of mass customization.
From the Lean Production perspective, an adverse effSlackf Slack can result from actions that require time, space, resources, or time but do not provide value from a customer’s point of view. CertaSlackpes of Slack can be wasted in excess, including an inventory of work-in-progress materials and inefficient time.
Eliminating waste is an effective driver of improvement, which allows problems that could be improved to be recognized. So, slack as a possible source of waste must be analyzed and eliminated in line with the Lean method of continuous improvement.
EXAMPLES OF SLACK
Daily Huddles
The strategy of deployment is redundancy.
What is the reason Slack can Slack be implemented? Daily huddles allow participants to share information or discuss the status of production and tasks that must be executed. These meetings are crucial in the constantly changing where unexpected situations occur. TSlacknds of Slack may be observed: (i) double checking the existing conditions for performing tasks (e.g., safety measures, resources available) and (ii) taking into consideration diverse perspectives in making decisions because nocann can conceive and implement practical solutions.