Product lifetime

Product lifetime or product lifespan is the time interval from when a product is sold to when it is discarded.[1] and Oguchi et al.[2] More specifically:

Product lifetime refers to the useful life of a product; the time during which the product remains integer and usable for its primary function for which it was conceived and produced".[3]:867

So to Ertz et al. (2019) this excludes recycling. Product lifetime is slightly different from service life because the latter consider only the effective time the product is used.[1] It is also different from product economic life which refers to the point where maintaining a product is more expensive than replacing it;[4] from product technical life which refers to the maximum period during which a product has the physical capacity to function;[5] and from the functional life which is the time a product should last regardless of external intervention to increase its lifespan.[6]

Product lifetime represent an important area of enquiry with regards to product design, the circular economy[7] and sustainable development.[5] This is because products, with the materials involved in their design, production, distribution, use and disposal (across their life cycle), embody carbon due to the energy involved in these processes.[8] Therefore, if product lifetimes can be extended, the use of energy, embodied in carbon, can be reduced and progress can be made towards reducing greenhouse gas emissions: Bocken et al.[9] term this "Slowing resource loops" (309, their emphasis). In addition, excessive waste generation has been attributed to short-lived goods and a throwaway society.[10]

In recent years, there has been a growth in academic and policy discussions around product lifetimes. For example, discussion of product lifetimes are an integral part of the European Commission's action plan for the circular economy[11]. In academia, the PLATE (Product Lifetimes and the Environment) Consortium hosts regular conferences and seminars around the topic of product lifetimes and the environment (see: http://www.plateconference.org/). In the business world, the Canadian Kijiji platform's Secondhand Economy Index examines how consumers extend product lifetime through secondhand markeplaces, swapping, donating and renting/leasing/lending/pooling (see: https://www.kijiji.ca/kijijicentral/second-hand-economy/).

This article examines how product lifetimes are defined in the academic literature and discusses how product lifetimes can be measured. A distinction is made between the definition and measurement of actual and expected product lifetimes.

Defining product lifetimes

Definitions of product lifetimes vary depending on what aspects those conducting research are interested in. Generally, actual product lifetimes refer to the actual time that a product exists in a particular state.[1] In contrast, expected product lifetimes refer to users' expectations for the lifetime of a product.[12] Additionally, actual and expected product lifetimes are influenced by durability and longevity; these concepts are briefly outlined below.

Durability is described by Cooper[13] as "the ability of a product to perform its required function over a lengthy period under normal use conditions of use without excessive expenditure on maintenance or repair" (p. 5). In contrast, longevity encompasses more than just the material properties of the product.[5] Cooper[5] notes that user behaviour, and broader social and cultural trends play important roles in the product's longevity. The paragraphs below outline the definitions of actual and expected product lifetimes.

Actual product lifetimes

Exhaustive work has been undertaken by Murakami et al.[1] and Oguchi et al.[2] and to outline several definitions and discuss methods for identifying actual product lifetimes. Murkami et al.[1] identify the following overarching concepts in product lifetime definitions which are discussed below: Age, Residential time, Service life, Possession span and Duration of use.

Age

A product's age is the time from when the product was created to either the present or "the time of interest" (:[1] 600) for the researchers.

Residential time

Residential time is considered to be time in which a product, its constituent materials and parts, exists in society.[1] Residential time includes the time in which a product may be broken and/ or discarded.[1]

Service life
Main article: Service life

According to Murkami et al.,[1] the service life of a product refers to the duration of time for which products continue to work and can be used.

Possession span

The possession span is the period of time that a user has possession of the product.[1]

Duration of use

The duration of use indicates how long a user uses the product for.[1] Murkami et al.[1] distinguish duration of use from Service life by noting that duration of use is measured for a specific user, whereas Service life describes the total in-service use of the product for all its users (accounting for transfers of ownership e.g. reuse). Additionally, possession span is distinguished from duration of use, as possession span includes "dead storage" (:[1] 601) time, where a product is owned by a user but not in use (i.e. in storage).

Product lifetime extension

Definition

The perceived shortening of product lifetime and the prominent issue of planned obsolescence have led many researchers to study how product lifetime might be extended. The PLE concept operationalizes in practice the circular or closed loop ecoomy (i.e., cradle-to-cradle model). PLE contributes substantially to the "starting loop strategy" and the "slowing loop strategy" pertaining to the ciruclar economy, by prolonging the useful life of products through design for long-life, called "nature strategies" (i.e., starting loop strategy), as well as by life extending measures such as repair, remanufacturing, refurbishment, reconditioning and reuse, called "nurture strategies" (i.e., slowing loop strategy).[3]

PLE encompasses behaviors, processes, systems, and procedures by consumers or organizations, contributing both to product nature and/or nurture. More specifically, PLE strategies enhance the useful life of a product, in design (i.e., nature), as well as through maintenance and prolonged use with a consumer or [...] actors (i.e. nurture)[3](p. 868).

The Table below shows the various nature and nurture strategies for product lifetime extension.

PLE strategyActivitiesSub-activitiesDefinition
NatureImproved product designImproved product and production processUse of more durable parts, components, and production processes
NatureImproved product designImproved design for repairBetter design for repair, remanufacturing, refurbishing, and reconditioning; Design for up-datable or up-gradable products that do not have to be replaced in their entirety.
NurtureAccess schemesAccess schemes (use-oriented service scape)Leasing: the lessee pays a regular fee for unlimited and individual use of the product.[14][15][16][17]
NurtureAccess schemesAccess schemes (use-oriented service scape)Renting: the customer uses the product individually for a predetermined period.[14][15][16][17]
NurtureAccess schemesAccess schemes (use-oriented service scape)Mutualising: the product is sequentially used by different customers.[14][15][16][17]
NurtureAccess schemesAccess schemes (use-oriented service scape)Pooling: the simultaneous use of a product by different customers.[14][15][16][17]
NurtureMaintenanceMaintenance (product-oriented scape)Maintenance contracts: involve (extended) warranty, spare parts and consumables delivery, inspection and diagnosis, updates/upgrades, cleaning/safe-keeping, and product installation/start-up/commissioning.[14]
NurtureMaintenanceAdvice (product-oriented service scape)Advice contracts: through help desks, the provider dispenses information and assistance to customers regarding the management of product use, maintenance and repair (in case of self-repair) via phone, email, and internet services, allowing direct access to the supplier database.[14]
NurtureMaintenanceTraining (product-oriented service scape)Training contracts: the provider offers training services to support the client while defining how to use a product and obtain best performance, improving the product efficiency during use while assuring the safety and/or improving the business.[14]
NurtureMaintenanceConsultancy (product-oriented service scape)Consultancy contracts: The provider offers consulting services to the customer regarding product development and use, as well as on business improvements.[14]
NurtureRedistributionDonationFree passing of goods from one consumer who does not use it anymore to another consumer who needs it.[15][16][18][17]
NurtureRedistributionSwappingDirect exchange of goods where no money or equivalent medium is involved. Goods may also be exchanged for services and services for goods.[15][16][18][17]
NurtureRedistributionSecondhand marketplaceExchange between two parties involving the transfer of a preowned good in exchange for an amount of money considered equivalent to it.[15][16][18][17]
NurtureRecoveryProduct repairrepair: A provider offers repair services that may be performed on- or off-site, directly or remotely, programmed or available 24/7 for emergencies.
NurtureRecoveryProduct repairPreventive reparation: reparation programs that are defined by a contract may be proposed in standard, customised or special formats.
NurtureRecoveryProduct repairFull-reparation contract: A provider is completely responsible for the product performance. These solutions are nearly always provided through a package.
NurtureRecoveryRemanufacturing / refurbishing / repackaging / reconditioningThe provider remanufactures, refurbishes or reconditions existing products typically sourced from reverse logistics systems, inverse supply chain, take back schemes, trade-in programs, buy-back offers, or commercial returns. The provider offers a like-new product, often with a like-new warranty and a new serial number starting from an old product that has been completely or partially disassembled and rebuilt up to include all product updates.

Source: Ertz, M., Leblanc-Proulx, S., Sarigöllü, E., & Morin, V. (2019). Made to break? A taxonomy of business models on product lifetime extension. Journal of Cleaner Production; Ertz, M., Leblanc-Proulx, S., Sarigöllü, E., & Morin, V. (2019). Advancing quantitative rigor in the circular economy literature: New methodology for product lifetime extension business models. Resources, Conservation and Recycling, 150, 104437.

Product lifetime extension business models (PLEBM)

PLE is enacted through various entities that can be generically denominated as product lifetime extension business models (PLEBM) and which aim at improving product design (nature strategies)[19][20] or increase the lifetime of the product during post-production phases (nurture strategies).[6] Any organization could constitute a PLEBM for as long as it contributes to increase product lifetime. The Product lifetime extension business model (PLEBM) framework is a typology of PLE business models based on Osterwalder and Pigneur's (2010) framework. Any business extending product lifetime to some extent can be descirbed along seven key dimensions.[3] The integration of peers (i.e., consumers) as key partners in the PLEBM framework, shows the importance of individual consumers in PLE efforts, and the framework draws a direct link between PLE and the sharing economy.[3] A typology based on the "key activities" and "key partners" dimensions, any company that engages in PLE practices belongs to any one of the seven models on product lifetime extension, as follows:[3]

  • "Relational product-as-a-service":[3] Mainly large corporate manufacturers (e.g., Samsung, Toshiba). They create value byproviding maintenance2and recovery, especially reparation (81.6%). Products are sourced by organizations (100.0%), but peersare also providers because these organizations are not onlyinvolved in B2B (81.60%) but also B2C/C2B configurations (50.0%).For example,Samsung or Toshiba provide repair and maintenanceservice to corporate clients but also to end users, i.e. consumers who may encounter issues with their smartphones, tablets or lap-tops. Consistent with their service orientation, a relatively highshare of these organizations uses direct channels such as techni-cians and salespeople who intervene in client premises. Hence, thecustomer relationship is mainly relational (78.9%), and the highshare of transactional relationships (68.4%) may be associated with the B2C segments, since large corporations lack direct contact withconsumers as opposed to their business partners. For example,Cisco Certified Technicians work with the Technical AssistanceCenter to, quickly and efficiently, resolve support incidents at clientsites. As such, the revenue stream consists mainly of usage fee(63.2%) with service agreements, and asset sales (55.3%).
  • Brick&click product nurturer:[3] Many car (e.g., Mercedes-Benz, BMW, Audi, VW, Toyota, Volvo, Renault-Nissan) and truck/engine (e.g., Iveco, Komatsu, Caterpillar, Scania) companies belong to this group. They conduct virtually all types of PLE activities, except product design.They specialize in both maintenance (100.0%) and recovery(100.0%), while redistribution (76.5%), access (64.7%), and remanufacturing (58.8%) activities are less systematic. In addition to the organization-provided products, some companies also rely on peers to source products. The scope of the different maintenance services varies from tracking of repair activities (Iveco), recommendation of optimum machines, optionsand attachments (Komatsu), consumables and spare parts delivery (Volvo, Volkswagen), to client information concerning the nearestservice center in case of failure (Audi, BMW). In contrast to relational product-as-a-service, Brick&click product nurturer offer redistribution and access opportunities, spanning more comprehensively the continuum of product nurturing activities. Hence, the revenue model is more diversified, namely with asset sale as well as lending/renting/leasing, and licensing, in addition to usage fee. Although mostly using physicalstores (i.e., bricks) and direct channels, these organizations also rely heavily on digital platforms (i.e. click), but in interactive rather thantransactional form.
  • Quality product designer:[3] These companies can be roughly divided into two groups: organizations that manufacture high-end luxury (e.g.Louis Vuitton, Mont-Blanc, Rolex); and organizations that produce massconsumption goods with superior product design (e.g., Apple, Lego, Patagonia). They focus on superior design while offering repairand recovery solutions. They uniquely focus on product superior design (100%), or product “nature” rather than “nurture”. Some also perform maintenance (72.2%), and re-covery in the form of reparation (55.6%). Hence, together with Brick&click product nurturers, they span across a broad array of activities. However, in contrast to Brick-and-click product nurturers specializing on PLE activities improving the nurture of products (i.e., maintenance and recovery), quality product designer focus on activities improving the nature of products. Thus, stores, as well as transactional platforms and mail/transport, constitute predominant channels of product sourcing. As some of these organizations generate revenues through usage fee (76.5%), typically through maintenance con-tracts, a higher share relies on asset sale (82.4%).
  • Secondhand vendor:[3] second hand organizations create value through redistribution only(e.g., Amazon, eBay, The Salvation Army). These organizations facilitate the return or exchange of pre-owned products from peers. Although these organizations have an exclusively transactional orientation, their channels vary from stores to transactional platforms, including mail/transportation. The type of revenue stream ranges from asset sale (the vast majority) to brokerage fee (30.8%) while other streams are more marginal. The Salvation Army or Ikea, for example, mostly rely on asset sale, while eBay takes brokerage fees for each exchange conducted on the transactional platform. These business models are comprised within the larger sharing economy.
  • Marketer-managed access system:[3] such organizations create value by providing access to needed products through digital transactional platforms (75.0%), stores (34.4%) or fixed touchpoints (31.3%) (e.g., Car2Go, Getable, Velib). This cluster can be labelled marketer-managed access system as it comprises organizations, which lend, rent or lease their assets without allowing peers to source products by themselves or exchange with each other (i.e., C2C). Popularly misquoted as sharing systems, these organizations clustering confirm that the sharing denomination is misleading. Subscription fees (71.9%) prevail, while lending/renting/leasing fees (68.8%) follow closely.
  • Peer-to-peer access broker:[3] In contrast to marketer-manager access systems, peer-to-peer access brokers consist of mostly digital transactional platforms (88.9%) allowing peers (100.0%) rather than organizations (5.6%) to source products, in mostly C2C exchange configurations (34.4%). For example, Drivy or Turo are both peer-to-peer car rental platforms; Boatsetter is a C2C boat rental site; while peer-to-peer rental websites Sharetribe or Peerby stretch across a wider range of product categories. Corresponding revenue models are predominantly brokerage fee (88.9%). These organizations position themselves as PLE champions since their PLE activities are core (100.0%) to their business model. These business models are comprised within the larger sharing economy.
  • Consumer redistribution marketplace:[3] similarly to secondhand vendor, these organizations focus on redistribution only (100.0%). However, similarly to P2P access brokers, consumer redistribution marketplaces rely exclusively on peers (100.0%) for product sourcing. Exchange configurations involve most frequently peers only (78.6%), but also B2C/C2B exchanges (42.9%). Peers touchpoints (71.4%) or mail/transport (64.3%) channels prevail. Again, the web appears as a powerful enabler for peer-powered exchanges since both transactional (57.1%) and interactive (42.9%) channels are used (e.g., Kijiji, Craigslist). However, the website does not support online transaction. Actual transactions are conducted offline with peers (i.e., peers touchpoints). Although no specific revenue model seems to stand out in this cluster, it is worth noting that advertising revenues are at their highest level (42.9%). These organizations refer simultaneously to peer-to-peer, sharing economy and second hand.

Another typology classified product lifetime extension business models according to their PLE key activities (see Table 1) and their revenue stream (i.e., asset sale, asset renting, licensing, usage fee, subscription fee, advertising, and donation/crowdfunding) and found five groups of business models:[21]

1) Group V: maintenance and recovery/asset sale and usage fee (e.g., Cisco, ABB, IBM, Xerox);[21] 2) Group W: Access, maintenance, redistribution and recovery/asset sale, asset renting, licensing, and usage fee (e.g., Toyota, Audi, Renault-Nissan, BMW, Volkswagen);[21] 3) Group X: redistribution/asset sale (e.g., Kijiji, Craigslist, LesPAC). Since many peer-to-peer exchanges are involved, this group relates to the sharing economy;[21] 4) Group Y: access schemes/asset renting, subscription fee (e.g., Bixi, Communauto, Zipcar);[21] 5) Group Z: access schemes/brokerage fee (e.g., Boatsetter, Peerby, KitSplit). Similarly to Group X, since many peer-to-peer exchanges are involved, this group relates to the sharing economy.[21]

Expected product lifetimes

A conference paper by Oguchi et al.[12] sought to identify and test differences in definitions of product lifetime expectations. Oguchi et al.[12] illustrated that previous research into expected product lifetimes has been inconsistent in its use of the term expected product lifetimes. For example, Cooper[22] enquires about "reasonable" expected lifetimes, while Brook Lyndhurst[23][24] discusses "normal" expected lifetimes. Wieser et al.[25] identified the tension between everyday expectations and desires, distinguishing between these expectations in his study of 21 products. In addition, earlier work by Tasaki et al.[26] and more recent work by WRAP[27] have asked users to report both how long they have owned an item for, and how long they expect to use the item for in future: WRAP[27] term this "active use". Building on these previous studies (described above), Oguchi et al.[12] identified and tested three distinct definitions of expected product lifetimes, these are outlined below.

Intended lifetime

Oguchi et al.[12] define the intended lifetime as the length of time for which a user intends to use the product in question.

Ideal lifetime

The ideal length of time for which a user expects their product to last. Oguchi et al.[12] describe this as "the highest preference of consumers".

Predicted lifetime

The realist prediction by the user of how long a product will last. The user is thought to make this prediction based on their previous experiences and "other relevant factors" (Oguhci et al.[12]).

Measuring product lifetimes

Academic enquiry into the product lifetimes of electrical and electronic equipment was undertaken in 2000 by Cooper and Mayers[28] who conducted household interviews and focus groups to establish the age at discard (actual product lifetime) and expected lifetimes for 17 products. Since this study, work has been undertaken by other academics into measuring actual and expected product lifetimes; the methods employed are outlined below.

Actual product lifetimes

Actual product lifetimes can be measured using a variety of methods which include: product testing, discard surveys, user interviews and modelling. These are discussed below.

Product testing

Products can be tested under laboratory conditions to assess their lifetime under different conditions of use.[5]

Discard surveys

Oguchi et al.[2] identify that surveys of waste treatment and recycling facilities can provide information on the age of the appliance at break or discard. Identifying information such as the product serial and/ or batch number can be used to find out a date of manufacturer from which the age of the appliance at break or discard can be calculated.

User interviews

Cooper and Mayers[28] conducted household interviews to establish the age of 17 electrical and electronic items at discard and break. However it has been noted that user interviews are subject to the accuracy of memory, and that reviews of products which have failed in the past only provides information on "a historical situation" (:[5] p. 10), not taking into account the features and lifetime of extant products.

Modelling

Product lifetimes can be modelled using extant data from surveys with the application of probability and other statistical concepts (e.g. distributions).[2][29] One of the earliest attempts to estimate product lifetimes was undertaken by Pennock and Jaeger[30] who utilised actuarial methods to measure the Service life of household goods for one owner. In the 1990s, Bayus[31] modelled car replacement rates and Bayus and Gupta[32] evaluated the user decision making process and factors around replacement car purchases.[32] In 2010, Oguchi et al.[2] proposed modelling product lifetimes factoring the total number of products shipped and discarded in a year. Oguchi et al.[2] outlined a series of equations which represent lifespan distributions for a given product at a particular point in time.

Expected product lifetimes

Expected product lifetimes are measured at the individual level using survey methods and collectively using focus groups. With the exception of Oguchi et al.[12] and Wieser et al.,[25] many studies into expected product lifetimes have not distinguished between the different definitions (outlined above). The methods for measuring expected product lifetimes are outlined below.

Survey methods

Survey methods into expected product lifetimes encompass online questionnaires,[12][25] household[28] and telephone[33] interviews. These studies asked individual participants to report their expectations for product lifetimes in units of time. Survey methods (such as Oguchi et al.[12]) can also use Likert items to evaluate if current products meet users expectations with regards to durability and longevity.

Focus groups

Focus groups can be convened where participants take part in discussions to reach a group consensus on product lifetime expectations.[24]

gollark: I've mostly fixed the program now, so it appears to roughly match the Haskell version and produce nice images.
gollark: That's a gecko? I thought they were bigger.
gollark: https://media.discordapp.net/attachments/348702212110680064/733705583458385992/out.pngI fixed a bug and it works *somewhat* right now. Though the brightness is still broken.
gollark: For some reason it did that the FIRST time, and now made this, which looks less good.
gollark: I'm trying to port a Haskell art generator program thing (https://github.com/TomSmeets/FractalArt/blob/master/src/Main.hs) to Rust and this... kind of works?

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