Product lifetime

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.

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 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]

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.

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

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).

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.

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.

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]

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.

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

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".

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]).

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.

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

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.

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.

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